Merge pull request leereilly#157 from Casmo/patch-5

Added OpenTTD fixing leereilly#156

README.md

@@ -328,6 +328,7 @@ A selection of major game studios, publishers, etc. using GitHub:
 * [openage](https://github.com/SFTtech/openage) - Clone of the Age of Empires II engine.
 * [OpenDungeons] (https://github.com/OpenDungeons/OpenDungeons) - Open source game inspired by Dungeon Keeper - Dark, damp and dangerous...
 * [OpenRA](https://github.com/OpenRA/OpenRA) - Open-source implementation of the Red Alert engine using .NET/mono and OpenGL. Runs on Windows, Linux and OSX.
+* [OpenTTD](https://github.com/OpenTTD/OpenTTD) - OpenTTD is a transport simulation game based upon the popular game Transport Tycoon Deluxe, written by Chris Sawyer.
 * [OpenXcom](https://github.com/SupSuper/OpenXcom) - Clone of the original X-COM.
 * [Pax Britannica](https://github.com/henkboom/pax-britannica) - Underwater one-button real-time strategy game.
 * [PCOTM (Phone Case of the Monster)](https://github.com/jwoertink/pcotm) - Ruby game, where you play as a phone-collecting monster.