Documentation: Expand installation.md

See: #503

installation.md

@@ -1,3 +1,21 @@
 # Installation
 
-JGR's patchpack can be installed by downloading one of the binaries in [releases](https://github.com/JGRennison/OpenTTD-patches/releases), by [compiling](/COMPILING.md) yourself, or using [homebrew](https://brew.sh) on macOS by typing `brew install jgrennison-openttd --cask`
+## Windows
+
+Download the Windows zip file for your OS type (usually the 64 bit version) from [releases](https://github.com/JGRennison/OpenTTD-patches/releases).
+
+Unzip this file and run `openttd.exe`.
+
+## Linux
+
+Download and use one of the Linux builds in [releases](https://github.com/JGRennison/OpenTTD-patches/releases), or compile from source (see below).
+
+## MacOS
+
+Download and use the MacOS DMG file from [releases](https://github.com/JGRennison/OpenTTD-patches/releases).
+
+Alternatively, use [homebrew](https://brew.sh) by typing `brew install jgrennison-openttd --cask`.
+
+## Compiling your own build
+
+See [compiling](/COMPILING.md) for more details.