Extract manual installation instructions

Alacritty's manual installation instructions take up a lot of space in
the README and they are hard to navigate because there's a lot of
information for specific distros which are irrelevant to most users.

To improve this situation, the manual installation section has been
moved to the `INSTALL.md` file. This allows keeping the readme to a
minimum which just includes the straight-forward instructions required
to install it on systems which provide packages for it.

Having a separate file also makes it possible to add a full index just
for the installation instructions, which makes it possible to skip
sections which are irrelevant.

1 files changed, 2 insertions, 296 deletions

diff --git a/README.md b/README.md
index f9a7da57..efd2f5b6 100644
--- a/README.md
+++ b/README.md
@@ -36,12 +36,8 @@ built from source.
 
 ## Installation
 
-Some operating systems already provide binaries for Alacritty, for everyone else there are
-instructions to compile Alacritty from source.
-
-For the manual installation, please first read the [prerequisites](#prerequisites) section,
-then find the instructions for your OS, and finally go through the [building](#building)
-and [configuration](#configuration) steps.
+Some operating systems already provide binaries for Alacritty, for everyone else the instructions
+to build Alacritty from source, can be found [here](INSTALL.md).
 
 ### Arch Linux
 
@@ -72,296 +68,6 @@ zypper in alacritty
 xbps-install alacritty
 ```
 
-### FreeBSD
-```sh
-pkg install alacritty
-```
-
-## Manual Installation
-
-### Prerequisites
-
-1. Alacritty requires the most recent stable Rust compiler; it can be installed with
-   `rustup`.
-
-#### Installing Rust compiler with `rustup`
-
-1. Install [`rustup.rs`](https://rustup.rs/).
-
-2. Clone the source code:
-
-   ```sh
-   git clone https://github.com/jwilm/alacritty.git
-   cd alacritty
-   ```
-
-3. Make sure you have the right Rust compiler installed. Run
-
-   ```sh
-   rustup override set stable
-   rustup update stable
-   ```
-
-#### Debian/Ubuntu
-
-You can build alacritty using `cargo deb` and use your system's package manager
-to maintain the application using the instructions [above](#debianubuntu).
-
-If you'd still like to build a local version manually, you need a few extra
-libraries to build Alacritty. Here's an apt command that should install all of
-them. If something is still found to be missing, please open an issue.
-
-```sh
-apt-get install cmake libfreetype6-dev libfontconfig1-dev xclip
-```
-
-#### Arch Linux
-
-On Arch Linux, you need a few extra libraries to build Alacritty. Here's a
-`pacman` command that should install all of them. If something is still found
-to be missing, please open an issue.
-
-```sh
-pacman -S cmake freetype2 fontconfig pkg-config make xclip
-```
-
-#### Fedora
-
-On Fedora, you need a few extra libraries to build Alacritty. Here's a `dnf`
-command that should install all of them. If something is still found to be
-missing, please open an issue.
-
-```sh
-dnf install cmake freetype-devel fontconfig-devel xclip
-```
-
-#### CentOS/RHEL 7
-
-On CentOS/RHEL 7, you need a few extra libraries to build Alacritty. Here's a `yum`
-command that should install all of them. If something is still found to be
-missing, please open an issue.
-
-```sh
-yum install cmake freetype-devel fontconfig-devel xclip
-yum group install "Development Tools"
-```
-
-#### openSUSE
-
-On openSUSE, you need a few extra libraries to build Alacritty. Here's
-a `zypper` command that should install all of them. If something is
-still found to be missing, please open an issue.
-
-```sh
-zypper install cmake freetype-devel fontconfig-devel xclip
-```
-
-#### Slackware
-
-Compiles out of the box for 14.2
-For copy & paste support (middle mouse button) you need to install xclip
-https://slackbuilds.org/repository/14.2/misc/xclip/?search=xclip
-
-
-#### Void Linux
-
-On [Void Linux](https://voidlinux.eu), install following packages before
-compiling Alacritty:
-
-```sh
-xbps-install cmake freetype-devel freetype expat-devel fontconfig-devel fontconfig xclip
-```
-
-#### FreeBSD
-
-On FreeBSD, you need a few extra libraries to build Alacritty. Here's a `pkg`
-command that should install all of them. If something is still found to be
-missing, please open an issue.
-
-```sh
-pkg install cmake freetype2 fontconfig xclip pkgconf
-```
-
-#### OpenBSD
-
-Alacritty builds on OpenBSD 6.3 almost out-of-the-box if Rust and
-[Xenocara](https://xenocara.org) are installed.  If something is still found to
-be missing, please open an issue.
-
-```sh
-pkg_add rust
-```
-
-#### Solus
-
-On [Solus](https://solus-project.com/), you need a few extra libraries to build
-Alacritty. Here's a `eopkg` command that should install all of them. If
-something is still found to be missing, please open an issue.
-
-```sh
-sudo eopkg install fontconfig-devel
-```
-
-#### NixOS/Nixpkgs
-
-The following command can be used to get a shell with all development
-dependencies on [NixOS](https://nixos.org).
-
-```sh
-nix-shell -A alacritty '<nixpkgs>'
-```
-
-#### Gentoo
-
-On Gentoo, there's a portage overlay available. Make sure `layman` is installed
-and run:
-
-```sh
-sudo layman -a slyfox
-```
-
-Then, add `x11-terms/alacritty **` to `/etc/portage/package.accept_keywords` and
-emerge alacritty:
-
-```sh
-sudo emerge alacritty
-```
-
-It might be handy to mask all other packages provided in the `slyfox` overlay by
-adding `*/*::slyfox` to `/etc/portage/package.mask` and adding
-`x11-terms/alacritty::slyfox` to `/etc/portage/package.unmask`.
-
-### Cargo
-
-If you have a rust toolchain setup you can install Alacritty via cargo:
-
-```sh
-cargo install --git https://github.com/jwilm/alacritty
-```
-
-Note that you still need to download system build dependencies via your package
-manager as mentioned above. The binary `alacritty` will be placed into `$HOME/.cargo/bin`.
-Make sure it is in your path (default if you use `rustup`).
-
-#### Other
-
-If you build Alacritty on another distribution, we would love some help
-filling in this section of the README.
-
-### Building
-
-**BEFORE YOU RUN IT:** Install the config file as described below; otherwise,
-many things (such as arrow keys) will not work.
-
-#### Linux
-
-Once all the prerequisites are installed, compiling Alacritty should be easy:
-
-```sh
-cargo build --release
-```
-
-If all goes well, this should place a binary at `target/release/alacritty`.
-
-
-##### Desktop Entry
-
-Many linux distributions support desktop entries for adding applications to
-system menus. To install the desktop entry for Alacritty, run
-
-```sh
-sudo cp target/release/alacritty /usr/local/bin # or anywhere else in $PATH
-sudo desktop-file-install alacritty.desktop
-sudo update-desktop-database
-```
-
-#### MacOS
-
-To build an application for macOS, run
-
-```sh
-make app
-cp -r target/release/osx/Alacritty.app /Applications/
-```
-
-## Manual Page
-
-Installing the manual page requires the additional dependency `gzip`.
-To install the manual page, run
-
-```sh
-sudo mkdir -p /usr/local/share/man/man1
-gzip -c alacritty.man | sudo tee /usr/local/share/man/man1/alacritty.1.gz > /dev/null
-```
-
-## Shell completions
-
-To get automatic completions for alacritty's flags and arguments you can install the provided shell completions.
-
-### Zsh
-
-To install the completions for zsh, you can place the `alacritty-completions.zsh` as `_alacritty` in any directory referenced by `$fpath`.
-
-If you do not already have such a directory registered through your `~/.zshrc`, you can add one like this:
-
-```sh
-mkdir -p ${ZDOTDIR:-~}/.zsh_functions
-echo 'fpath+=${ZDOTDIR:-~}/.zsh_functions' >> ${ZDOTDIR:-~}/.zshrc
-```
-
-Then copy the completion file to this directory:
-
-```sh
-cp alacritty-completions.zsh ${ZDOTDIR:-~}/.zsh_functions/_alacritty
-```
-
-### Bash
-
-To install the completions for bash, you can `source` the `alacritty-completions.bash` in your `~/.bashrc` file.
-
-If you do not plan to delete the source folder of alacritty, you can run
-
-```sh
-echo "source $(pwd)/alacritty-completions.bash" >> ~/.bashrc
-```
-
-Otherwise you can copy it to the `~/.bash_completion` folder and source it from there:
-
-```sh
-mkdir -p ~/.bash_completion
-cp alacritty-completions.bash ~/.bash_completion/alacritty
-echo "source ~/.bash_completion/alacritty" >> ~/.bashrc
-```
-
-### Fish
-
-To install the completions for fish, run
-
-```
-sudo cp alacritty-completions.fish $__fish_datadir/vendor_completions.d/alacritty.fish
-```
-
-## Terminfo
-
-The terminfo database contains entries describing the terminal
-emulator's capabilities. Programs need these in order to function
-properly.
-
-Alacritty should work with the standard `xterm-256color` definition,
-but to allow programs to make best use of alacritty's capabilities,
-use its own terminfo definition instead.
-
-Unless the user has set the `TERM` environment variable in the
-alacritty configuration, the `alacritty` terminfo definition will be
-used if it has been installed. If not, then `xterm-256color` is used
-instead.
-
-To install alacritty's terminfo entry globally:
-
-```sh
-sudo tic -e alacritty,alacritty-direct alacritty.info
-```
-
 ## Configuration
 
 Although it's possible the default configuration would work on your system,