Document all not-so-obvious features (e.g. multiplayer, AI, networked game, planned UIs, etc)

• The game will be multiplayer, networked and it will allow the players to form teams, as described in docs/game-rules_en.md.
• The game will have an AI module that may replace as many players as needed. For a game to be possible, at least one human is needed.
• The game will be multithreaded.
• The primary OS is linux. Use as many cross-platform features as possible.
• The code should respect C99 standard and be at least POSIX compliant, if not POSIX conformant.
• The cutter framework will be used for unit testing.
• gcc should be used as the main compiler.
• We are using autotools for building the project as they are helpful for designing portable application.
• The UI interface should be developed in 2 stages: a CLI interface, using ncurses, and a GUI interface using GTK.
• There must be an API, to allow other developers to build other interfaces. The interface should not interfere with the game. It's only purpose is user interaction.
• The business logic of the application must be packaged as a library (or more, if it is needed) in order to use it for UI development.
• The build must be tested with valgrind.