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, 310 insertions, 0 deletions

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+# Manual Installation
+
+1. [Prerequisites](#prerequisites)
+    1. [Source Code](#clone-the-source-code)
+    2. [Rust Compiler](#install-the-rust-compiler-with-rustup)
+    3. [Dependencies](#dependencies)
+        1. [Debian/Ubuntu](#debianubuntu)
+        2. [Arch Linux](#arch-linux)
+        3. [Fedora](#fedora)
+        4. [CentOS/RHEL 7](#centosrhel-7)
+        5. [openSUSE](#opensuse)
+        6. [Slackware](#slackware)
+        7. [Void Linux](#void-linux)
+        8. [FreeBSD](#freebsd)
+        9. [OpenBSD](#openbsd)
+        10. [Solus](#solus)
+        11. [NixOS/Nixpkgs](#nixosnixpkgs)
+        12. [Gentoo](#gentoo)
+        13. [Other](#other)
+2. [Building](#building)
+    1. [Linux](#linux)
+        1. [Desktop Entry](#desktop-entry)
+    2. [MacOS](#macos)
+    3. [Cargo](#cargo)
+3. [Manual Page](#manual-page)
+4. [Shell Completions](#shell-completions)
+    1. [Zsh](#zsh)
+    2. [Bash](#bash)
+    3. [Fish](#fish)
+5. [Terminfo](#terminfo)
+
+## Prerequisites
+
+### Clone the source code
+
+Before compiling Alacritty, you'll have to first clone the source code:
+
+```sh
+git clone https://github.com/jwilm/alacritty.git
+cd alacritty
+```
+
+### Install the Rust compiler with `rustup`
+
+1. Install [`rustup.rs`](https://rustup.rs/).
+
+3. To make sure you have the right Rust compiler installed, run
+
+   ```sh
+   rustup override set stable
+   rustup update stable
+   ```
+
+### Dependencies
+
+#### 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`.
+
+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
+
+### 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 $PATH
+sudo desktop-file-install alacritty.desktop
+sudo update-desktop-database
+```
+
+### MacOS
+
+To build an application for macOS, run
+
+```sh
+make app
+cp -r target/release/osx/Alacritty.app /Applications/
+```
+
+### Cargo
+
+If you don't want to clone the repository, you can install Alacritty directly using cargo:
+
+```sh
+cargo install --git https://github.com/jwilm/alacritty
+```
+
+## Manual Page
+
+Installing the manual page requires the additional dependency `gzip`.
+To install the manual page, run
+
+```sh
+sudo mkdir -p /usr/local/share/man/man1
+gzip -c alacritty.man | sudo tee /usr/local/share/man/man1/alacritty.1.gz > /dev/null
+```
+
+## Shell completions
+
+To get automatic completions for alacritty's flags and arguments you can install the provided shell completions.
+
+### Zsh
+
+To install the completions for zsh, you can place the `alacritty-completions.zsh` as `_alacritty` in any directory referenced by `$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
+```