Update Agent notification methods documentation (#14827)

* update health/notifications/README.md

* Alerta notification method documentation update

* Amazon SNS and some alerta changes

* notification methods imporvements

* alerta refinements

* awssns refinements

* custom alert refinements

* discord refinements

* email notifications documentation update

* flock notifications documentation update

* alerta edits

* awssns edits

* custom notification method edits

* discord edits

* email notification method edits

* flock edits

* IRC notifications update

* Kavenegar notifications documentation update

* matrix notifications documentation update

* messagebird notifications documentation update

* msteams notifications documentation update

* wording change

* twilio notifications documentation update

* telegram notifications documentation update

* syslog notifications update

* smstools3 notifications documentation update

* rocket.chat notifications documentation update

* pushover notifications documentation update

* pushbullet notifications documentation update

* prowl notifications documentation update

* pagerduty notifications documentation update

* remove comments from example configuration

* slight wording changes

* more notification methods documentation updates

* slack notification documentation update

* add config options to the notifications Introduction page

* crop image twilio

* crop image slack

* crop image pushover

* crop images pushbullet

* crop image messagebird

* crop image kavenegar

1 files changed, 56 insertions, 18 deletions

diff --git a/health/notifications/prowl/README.md b/health/notifications/prowl/README.md
index 8c155977d7..a574052978 100644
--- a/health/notifications/prowl/README.md
+++ b/health/notifications/prowl/README.md
@@ -1,21 +1,17 @@
-<!--
-title: "Prowl agent alert notifications"
-sidebar_label: "Prowl"
-custom_edit_url: "https://github.com/netdata/netdata/edit/master/health/notifications/prowl/README.md"
-learn_status: "Published"
-learn_topic_type: "Tasks"
-learn_rel_path: "Integrations/Notify/Agent alert notifications"
-learn_autogeneration_metadata: "{'part_of_cloud': False, 'part_of_agent': True}"
--->
+# Prowl Agent alert notifications
 
-# Prowl agent alert notifications
+Learn how to send notifications to Prowl using Netdata's Agent alert notification feature, which supports dozens of endpoints, user roles, and more.
 
-[Prowl](https://www.prowlapp.com/) is a push notification service for iOS devices.  Netdata
-supports delivering notifications to iOS devices through Prowl.
+> ### Note
+>
+> This file assumes you have read the [Introduction to Agent alert notifications](https://github.com/netdata/netdata/blob/master/health/notifications/README.md), detailing how the Netdata Agent's alert notification method works.
+
+[Prowl](https://www.prowlapp.com/) is a push notification service for iOS devices.  
+Netdata supports delivering notifications to iOS devices through Prowl.
 
 Because of how Netdata integrates with Prowl, there is a hard limit of
 at most 1000 notifications per hour (starting from the first notification
-sent).  Any alerts beyond the first thousand in an hour will be dropped.
+sent). Any alerts beyond the first thousand in an hour will be dropped.
 
 Warning messages will be sent with the 'High' priority, critical messages
 will be sent with the 'Emergency' priority, and all other messages will
@@ -23,10 +19,52 @@ be sent with the normal priority.  Opening the notification's associated
 URL will take you to the Netdata dashboard of the system that issued
 the alert, directly to the chart that it triggered on.
 
-## configuration
+## Prerequisites
+
+You will need:
+
+- a Prowl API key, which can be requested through the Prowl website after registering
+- terminal access to the Agent you wish to configure
+
+## Configure Netdata to send alert notifications to Prowl
+
+> ### Info
+>
+> This file mentions editing configuration files.  
+>
+> - To edit configuration files in a safe way, we provide the [`edit config` script](https://github.com/netdata/netdata/blob/master/docs/configure/nodes.md#use-edit-config-to-edit-configuration-files) located in your [Netdata config directory](https://github.com/netdata/netdata/blob/master/docs/configure/nodes.md#the-netdata-config-directory) (typically is `/etc/netdata`) that creates the proper file and opens it in an editor automatically.  
+> Note that to run the script you need to be inside your Netdata config directory.
+>
+> It is recommended to use this way for configuring Netdata.
+
+Edit `health_alarm_notify.conf`, changes to this file do not require restarting Netdata:
+
+1. Set `SEND_PROWL` to `YES`.
+2. Set `DEFAULT_RECIPIENT_PROWL` to the Prowl API key you want the alert notifications to be sent to.  
+   You can define multiple API keys like this: `APIKEY1, APIKEY2`.  
+   All roles will default to this variable if left unconfigured.
+
+You can then have different API keys per **role**, by editing `DEFAULT_RECIPIENT_PROWL` with the API keys you want, in the following entries at the bottom of the same file:
+
+```conf
+role_recipients_prowl[sysadmin]="AAAAAAAA"
+role_recipients_prowl[domainadmin]="BBBBBBBBB"
+role_recipients_prowl[dba]="CCCCCCCCC"
+role_recipients_prowl[webmaster]="DDDDDDDDDD"
+role_recipients_prowl[proxyadmin]="EEEEEEEEEE"
+role_recipients_prowl[sitemgr]="FFFFFFFFFF"
+```
+
+An example of a working configuration would be:
+
+```conf
+#------------------------------------------------------------------------------
+# iOS Push Notifications
+
+SEND_PROWL="YES"
+DEFAULT_RECIPIENT_PROWL="XXXXXXXXXX"
+```
 
-To use this, you will need a Prowl API key, which can be requested through
-the Prowl website after registering.
+## Test the notification method
 
-Once you have an API key, simply specify that as a recipient for Prowl
-notifications.
+To test this alert notification method refer to the ["Testing Alert Notifications"](https://github.com/netdata/netdata/blob/master/health/notifications/README.md#testing-alert-notifications) section of the Agent alert notifications page.