message: Add Arch Linux package install instructions
  Includes minor touch ups.
diff: @@ -29,11 +29,20 @@ binaries will be provided for supported operating systems.
  - [Announcing Alacritty, a GPU-Accelerated Terminal Emulator](http://blog.jwilm.io/announcing-alacritty/) January 6, 2017
  - [A short talk about Alacritty at the Rust Meetup January 2017](https://air.mozilla.org/rust-meetup-january-2017/) (starts at 57:00)
  -## Installation
  +## Package Installation
  -The only supported installation method at this time is from source. Proper
  -installers will be added prior to the 1.0 release of Alacritty. This section
  -will walk you through how to build from source on both macOS and Ubuntu.
  +The only supported installation method at this time is from source. Proper installers will be added prior to the 1.0 release of Alacritty.
  +
  +### Arch Linux
  +
  +```sh
  +git clone https://aur.archlinux.org/alacritty-git.git
  +cd alacritty-git
  +pacman -S rustup # needed until Rust 1.15 is available (see PR #131)
  +makepkg -isr
  +```
  +
  +## Manual Installation
  ### Prerequisites
  @@ -42,7 +51,7 @@ will walk you through how to build from source on both macOS and Ubuntu.
  2. Clone the source code:
  ```sh
  - git clone https://github.com/jwilm/alacritty
  + git clone https://github.com/jwilm/alacritty.git
  cd alacritty
  ```
  @@ -75,7 +84,7 @@ On Arch Linux, you need a few extra libraries to build Alacritty. Here's a
  to be missing, please open an issue.
  ```sh
  -pacman -S cmake freetype2 fontconfig xclip
  +pacman -S cmake freetype2 fontconfig pkg-config make xclip
  ```
  #### Fedora
  @@ -151,7 +160,7 @@ sudo cp target/release/alacritty /usr/local/bin # or anywhere else in $PATH
  cp Alacritty.desktop ~/.local/share/applications
  ```
  -### Configuration
  +## Configuration
  Although it's possible the default configuration would work on your system,
  you'll probably end up wanting to customize it anyhow. There is a default
  