Refactor collectors documentation (#7996)

* Initializing new structure

* Continuing with cleanup

* Modify old plugins conf

* Get rid of Add-more-charts and move links over

* More cleanup, add add-more-charts back in, build OK

* Cleanup and move content to reference

* Finish quickstart, add troubleshooting

* Sync what-is-netdata and fix typos

* Tweaks

* Finish quickstart, revamp collectors

* One more fix

1 files changed, 10 insertions, 259 deletions

diff --git a/README.md b/README.md
index a0c7c6b286..2bf9ce3c48 100644
--- a/README.md
+++ b/README.md
@@ -52,7 +52,7 @@ Netdata!](https://img.shields.io/twitter/url/http/shields.io.svg?style=social&la
 7.  [Infographic](#infographic) - Everything about Netdata in a single graphic
 8.  [Features](#features) - How you'll use Netdata on your systems
 9.  [Visualization](#visualization) - Learn about visual anomaly detection
-10. [What does it monitor?](#what-does-it-monitor) - See which apps/services Netdata auto-detects
+10. [What Netdata monitors](#what-netdata-monitors) - See which apps/services Netdata auto-detects
 11. [Documentation](#documentation) - Read the documentation
 12. [Community](#community) - Discuss Netdata with others and get support
 13. [License](#license) - Check Netdata's licencing
@@ -381,268 +381,19 @@ same range on all charts._
 > Highlighted ranges are propagated from Netdata server to Netdata server, when navigating via the [My nodes
 > menu](registry/README.md).
 
-## What does it monitor
-
-Netdata data collection is **extensible**. You can monitor anything you can get a metric for. Our [plugin
-API](collectors/plugins.d/) supports a variety of programming languages to make nearly anything a Netdata plugin: Go,
-Python, Node.js, Ruby, Java, Bash, Perl, and more!
-
--   For better performance, most system-related plugins (CPU, memory, disks, filesystems, networking, etc) have been
-    written in C.
--   For faster development and easier contributions, most application related plugins (databases, web servers, etc) have
-    been written in Go and Python.
-
-### APM (Application Performance Monitoring)
-
--   **[statsd](collectors/statsd.plugin/)** - Netdata is a fully featured statsd server.
--   **[Go expvar](collectors/python.d.plugin/go_expvar/)** - collects metrics exposed by applications written in the Go
-    programming language using the expvar package.
--   **[Spring Boot](collectors/python.d.plugin/springboot/)** - monitors running Java Spring Boot applications that
-    expose their metrics with the use of the Spring Boot Actuator included in Spring Boot library.
--   **[uWSGI](collectors/python.d.plugin/uwsgi/)** - collects performance metrics from uWSGI applications.
-
-### System Resources
-
--   **[CPU Utilization](collectors/proc.plugin/)** - total and per core CPU usage.
--   **[Interrupts](collectors/proc.plugin/)** - total and per core CPU interrupts.
--   **[SoftIRQs](collectors/proc.plugin/)** - total and per core SoftIRQs.
--   **[SoftNet](collectors/proc.plugin/)** - total and per core SoftIRQs related to network activity.
--   **[CPU Throttling](collectors/proc.plugin/)** - collects per core CPU throttling.
--   **[CPU Frequency](collectors/proc.plugin/)** - collects the current CPU frequency.
--   **[CPU Idle](collectors/proc.plugin/)** - collects the time spent per processor state.
--   **[IdleJitter](collectors/idlejitter.plugin/)** - measures CPU latency.
--   **[Entropy](collectors/proc.plugin/)** - random numbers pool, using in cryptography.
--   **[Interprocess Communication - IPC](collectors/proc.plugin/)** - such as semaphores and semaphores arrays.
-
-### Memory
-
--   **[ram](collectors/proc.plugin/)** - collects info about RAM usage.
--   **[swap](collectors/proc.plugin/)** - collects info about swap memory usage.
--   **[available memory](collectors/proc.plugin/)** - collects the amount of RAM available for userspace processes.
--   **[committed memory](collectors/proc.plugin/)** - collects the amount of RAM committed to userspace processes.
--   **[Page Faults](collectors/proc.plugin/)** - collects the system page faults (major and minor).
--   **[writeback memory](collectors/proc.plugin/)** - collects the system dirty memory and writeback activity.
--   **[huge pages](collectors/proc.plugin/)** - collects the amount of RAM used for huge pages.
--   **[KSM](collectors/proc.plugin/)** - collects info about Kernel Same Merging (memory dedupper).
--   **[Numa](collectors/proc.plugin/)** - collects Numa info on systems that support it.
--   **[slab](collectors/proc.plugin/)** - collects info about the Linux kernel memory usage.
-
-### Disks
-
--   **[block devices](collectors/proc.plugin/)** - per disk: I/O, operations, backlog, utilization, space, etc.
--   **[BCACHE](collectors/proc.plugin/)** - detailed performance of SSD caching devices.
--   **[DiskSpace](collectors/proc.plugin/)** - monitors disk space usage.
--   **[mdstat](collectors/proc.plugin/)** - software RAID.
--   **[hddtemp](collectors/python.d.plugin/hddtemp/)** - disk temperatures.
--   **[smartd](collectors/python.d.plugin/smartd_log/)** - disk S.M.A.R.T. values.
--   **[device mapper](collectors/proc.plugin/)** - naming disks.
--   **[Veritas Volume Manager](collectors/proc.plugin/)** - naming disks.
--   **[megacli](collectors/python.d.plugin/megacli/)** - adapter, physical drives and battery stats.
--   **[adaptec_raid](collectors/python.d.plugin/adaptec_raid/)** -  logical and physical devices health metrics.
--   **[ioping](collectors/ioping.plugin/)** - to measure disk read/write latency.
-
-### Filesystems
-
--   **[BTRFS](collectors/proc.plugin/)** - detailed disk space allocation and usage.
--   **[Ceph](collectors/python.d.plugin/ceph/)** - OSD usage, Pool usage, number of objects, etc.
--   **[NFS file servers and clients](collectors/proc.plugin/)** - NFS v2, v3, v4: I/O, cache, read ahead, RPC calls
--   **[Samba](collectors/python.d.plugin/samba/)** - performance metrics of Samba SMB2 file sharing.
--   **[ZFS](collectors/proc.plugin/)** - detailed performance and resource usage.
-
-### Networking
-
--   **[Network Stack](collectors/proc.plugin/)** - everything about the networking stack (both IPv4 and IPv6 for all
-    protocols: TCP, UDP, SCTP, UDPLite, ICMP, Multicast, Broadcast, etc), and all network interfaces (per interface:
-    bandwidth, packets, errors, drops).
--   **[Netfilter](collectors/proc.plugin/)** - everything about the netfilter connection tracker.
--   **[SynProxy](collectors/proc.plugin/)** - collects performance data about the linux SYNPROXY (DDoS).
--   **[NFacct](collectors/nfacct.plugin/)** - collects accounting data from iptables.
--   **[Network QoS](collectors/tc.plugin/)** - the only tool that visualizes network `tc` classes in real-time.
--   **[FPing](collectors/fping.plugin/)** - to measure latency and packet loss between any number of hosts.
--   **[ISC dhcpd](collectors/python.d.plugin/isc_dhcpd/)** - pools utilization, leases, etc.
--   **[AP](collectors/charts.d.plugin/ap/)** - collects Linux access point performance data (`hostapd`).
--   **[SNMP](collectors/node.d.plugin/snmp/)** - SNMP devices can be monitored too (although you will need to configure
-    these).
--   **[port_check](collectors/python.d.plugin/portcheck/)** - checks TCP ports for availability and response time.
-
-### Virtual Private Networks
-
--   **[OpenVPN](collectors/python.d.plugin/ovpn_status_log/)** - collects status per tunnel.
--   **[LibreSwan](collectors/charts.d.plugin/libreswan/)** - collects metrics per IPSEC tunnel.
--   **[Tor](collectors/python.d.plugin/tor/)** - collects Tor traffic statistics.
-
-### Processes
-
--   **[System Processes](collectors/proc.plugin/)** - running, blocked, forks, active.
--   **[Applications](collectors/apps.plugin/)** - by grouping the process tree and reporting CPU, memory, disk reads,
-    disk writes, swap, threads, pipes, sockets - per process group.
--   **[systemd](collectors/cgroups.plugin/)** - monitors systemd services using CGROUPS.
-
-### Users
-
--   **[Users and User Groups resource usage](collectors/apps.plugin/)** - by summarizing the process tree per user and
-    group, reporting: CPU, memory, disk reads, disk writes, swap, threads, pipes, sockets.
--   **[logind](collectors/python.d.plugin/logind/)** - collects sessions, users and seats connected.
-
-### Containers and VMs
-
--   **[Containers](collectors/cgroups.plugin/)** - collects resource usage for all kinds of containers, using CGROUPS
-    (systemd-nspawn, lxc, lxd, docker, kubernetes, etc).
--   **[libvirt VMs](collectors/cgroups.plugin/)** - collects resource usage for all kinds of VMs, using CGROUPS.
--   **[dockerd](collectors/python.d.plugin/dockerd/)** - collects docker health metrics.
-
-### Web Servers
-
--   **[Apache and lighttpd](collectors/python.d.plugin/apache/)** - `mod-status` (v2.2, v2.4) and cache log statistics,
-    for multiple servers.
--   **[IPFS](collectors/python.d.plugin/ipfs/)** - bandwidth, peers.
--   **[LiteSpeed](collectors/python.d.plugin/litespeed/)** - reads the litespeed rtreport files to collect metrics.
--   **[Nginx](collectors/python.d.plugin/nginx/)** - `stub-status`, for multiple servers.
--   **[Nginx+](collectors/python.d.plugin/nginx_plus/)** - connects to multiple nginx_plus servers (local or remote) to
-    collect real-time performance metrics.
--   **[PHP-FPM](collectors/python.d.plugin/phpfpm/)** - multiple instances, each reporting connections, requests,
-    performance, etc.
--   **[Tomcat](collectors/python.d.plugin/tomcat/)** - accesses, threads, free memory, volume, etc.
--   **[web server `access.log` files](collectors/python.d.plugin/web_log/)** - extracting in real-time, web server and
-    proxy performance metrics and applying several health checks, etc.
--   **[HTTP check](collectors/python.d.plugin/httpcheck/)** - checks one or more web servers for HTTP status code and
-    returned content.
-
-### Proxies, Balancers, Accelerators
-
--   **[HAproxy](collectors/python.d.plugin/haproxy/)** - bandwidth, sessions, backends, etc.
--   **[Squid](collectors/python.d.plugin/squid/)** - multiple servers, each showing: clients bandwidth and requests,
-    servers bandwidth and requests.
--   **[Traefik](collectors/python.d.plugin/traefik/)** - connects to multiple traefik instances (local or remote) to
-    collect API metrics (response status code, response time, average response time and server uptime).
--   **[Varnish](collectors/python.d.plugin/varnish/)** - threads, sessions, hits, objects, backends, etc.
--   **[IPVS](collectors/proc.plugin/)** - collects metrics from the Linux IPVS load balancer.
-
-### Database Servers
-
--   **[CouchDB](collectors/python.d.plugin/couchdb/)** - reads/writes, request methods, status codes, tasks,
-    replication, per-db, etc.
--   **[MemCached](collectors/python.d.plugin/memcached/)** - multiple servers, each showing: bandwidth, connections,
-    items, etc.
--   **[MongoDB](collectors/python.d.plugin/mongodb/)** - operations, clients, transactions, cursors, connections,
-    asserts, locks, etc.
--   **[MySQL and mariadb](collectors/python.d.plugin/mysql/)** - multiple servers, each showing: bandwidth, queries/s,
-    handlers, locks, issues, tmp operations, connections, binlog metrics, threads, innodb metrics, and more.
--   **[PostgreSQL](collectors/python.d.plugin/postgres/)** - multiple servers, each showing: per database statistics
-    (connections, tuples read - written - returned, transactions, locks), backend processes, indexes, tables, write
-    ahead, background writer and more.
--   **[Proxy SQL](collectors/python.d.plugin/proxysql/)** - collects Proxy SQL backend and frontend performance metrics.
--   **[Redis](collectors/python.d.plugin/redis/)** - multiple servers, each showing: operations, hit rate, memory, keys,
-    clients, slaves.
--   **[RethinkDB](collectors/python.d.plugin/rethinkdbs/)** - connects to multiple rethinkdb servers (local or remote)
-    to collect real-time metrics.
+## What Netdata monitors
 
-### Message Brokers
+Netdata can collect metrics from 200+ popular services and applications, on top of dozens of system-related metrics
+jocs, such as CPU, memory, disks, filesystems, networking, and more. We call these **collectors**, and they're managed
+by [**plugins**](collectors/plugins.d/), which support a variety of programming languages, including Go and Python.
 
--   **[beanstalkd](collectors/python.d.plugin/beanstalk/)** - global and per tube monitoring.
--   **[RabbitMQ](collectors/python.d.plugin/rabbitmq/)** - performance and health metrics.
+Popular collectors include **Nginx**, **Apache**, **MySQL**, **statsd**, **cgroups** (containers, Docker, Kubernetes,
+LXC, and more), **Traefik**, **web server `access.log` files**, and much more. 
 
-### Search and Indexing
+See the **full list of [supported collectors](collectors/COLLECTORS.md)**.
 
--   **[ElasticSearch](collectors/python.d.plugin/elasticsearch/)** - search and index performance, latency, timings,
-    cluster statistics, threads statistics, etc.
-
-### DNS Servers
-
--   **[bind_rndc](collectors/python.d.plugin/bind_rndc/)** - parses `named.stats` dump file to collect real-time
-    performance metrics. All versions of bind after 9.6 are supported.
--   **[dnsdist](collectors/python.d.plugin/dnsdist/)** - performance and health metrics.
--   **[ISC Bind (named)](collectors/node.d.plugin/named/)** - multiple servers, each showing: clients, requests,
-    queries, updates, failures and several per view metrics. All versions of bind after 9.9.10 are supported.
--   **[NSD](collectors/python.d.plugin/nsd/)** - queries, zones, protocols, query types, transfers, etc.
--   **[PowerDNS](collectors/python.d.plugin/powerdns/)** - queries, answers, cache, latency, etc.
--   **[dns_query_time](collectors/python.d.plugin/dns_query_time/)** - DNS query time statistics.
-
-### Time Servers
-
--   **[chrony](collectors/python.d.plugin/chrony/)** - uses the `chronyc` command to collect chrony statistics
-    (Frequency, Last offset, RMS offset, Residual freq, Root delay, Root dispersion, Skew, System time).
--   **[ntpd](collectors/python.d.plugin/ntpd/)** - connects to multiple ntpd servers (local or remote) to provide
-    statistics of system variables and optional also peer variables.
-
-### Mail Servers
-
--   **[Dovecot](collectors/python.d.plugin/dovecot/)** - POP3/IMAP servers.
--   **[Exim](collectors/python.d.plugin/exim/)** - message queue (emails queued).
--   **[Postfix](collectors/python.d.plugin/postfix/)** - message queue (entries, size).
-
-### Hardware Sensors
-
--   **[IPMI](collectors/freeipmi.plugin/)** - enterprise hardware sensors and events.
--   **[lm-sensors](collectors/python.d.plugin/sensors/)** - temperature, voltage, fans, power, humidity, etc.
--   **[Nvidia](collectors/python.d.plugin/nvidia_smi/)** - collects information for Nvidia GPUs.
--   **[RPi](collectors/charts.d.plugin/sensors/)** - Raspberry Pi temperature sensors.
--   **[w1sensor](collectors/python.d.plugin/w1sensor/)** - collects data from connected 1-Wire sensors.
-
-### UPSes
-
--   **[apcupsd](collectors/charts.d.plugin/apcupsd/)** - load, charge, battery voltage, temperature, utility metrics,
-    output metrics.
--   **[NUT](collectors/charts.d.plugin/nut/)** - load, charge, battery voltage, temperature, utility metrics, output
-    metrics.
--   **[Linux Power Supply](collectors/proc.plugin/)** - collects metrics reported by power supply drivers on Linux.
-
-### Social Sharing Servers
-
--   **[RetroShare](collectors/python.d.plugin/retroshare/)** - connects to multiple retroshare servers (local or remote)
-    to collect real-time performance metrics.
-
-### Security
-
--   **[Fail2Ban](collectors/python.d.plugin/fail2ban/)** - monitors the fail2ban log file to check all bans for all
-    active jails.
-
-### Authentication, Authorization, Accounting (AAA, RADIUS, LDAP) Servers
-
--   **[FreeRadius](collectors/python.d.plugin/freeradius/)** - uses the `radclient` command to provide freeradius
-    statistics (authentication, accounting, proxy-authentication, proxy-accounting).
-
-### Telephony Servers
-
--   **[opensips](collectors/charts.d.plugin/opensips/)** - connects to an opensips server (localhost only) to collect
-    real-time performance metrics.
-
-### Household Appliances
-
--   **[SMA webbox](collectors/node.d.plugin/sma_webbox/)** - connects to multiple remote SMA webboxes to collect
-    real-time performance metrics of the photovoltaic (solar) power generation.
--   **[Fronius](collectors/node.d.plugin/fronius/)** - connects to multiple remote Fronius Symo servers to collect
-    real-time performance metrics of the photovoltaic (solar) power generation.
--   **[StiebelEltron](collectors/node.d.plugin/stiebeleltron/)** - collects the temperatures and other metrics from your
-    Stiebel Eltron heating system using their Internet Service Gateway (ISG web).
-
-### Game Servers
-
--   **[SpigotMC](collectors/python.d.plugin/spigotmc/)** - monitors Spigot Minecraft server ticks per second and number
-    of online players using the Minecraft remote console.
-
-### Distributed Computing
-
--   **[BOINC](collectors/python.d.plugin/boinc/)** - monitors task states for local and remote BOINC client software
-    using the remote GUI RPC interface. Also provides alarms for a handful of error conditions.
-
-### Media Streaming Servers
-
--   **[IceCast](collectors/python.d.plugin/icecast/)** - collects the number of listeners for active sources.
-
-### Monitoring Systems
-
--   **[Monit](collectors/python.d.plugin/monit/)** - collects metrics about monit targets (filesystems, applications,
-    networks).
-
-### Provisioning Systems
-
--   **[Puppet](collectors/python.d.plugin/puppet/)** - connects to multiple Puppet Server and Puppet DB instances (local
-    or remote) to collect real-time status metrics.
-
-You can easily extend Netdata, by writing plugins that collect data from any source, using any computer language.
-
----
+Netdata's data collection is **extensible**, which means you can monitor anything you can get a metric for. You can even
+write a collector for your custom application using our [plugin API](collectors/plugins.d/README.md).
 
 ## Documentation