Add documentation for changing status using in-game chat

[derekjtong]

This pull request addresses a gap in documentation regarding the ability to change user status through direct chat messages with the Deceive user that appears in the in-game friends list. Specifically, users can send commands like online, offline, mobile, disable, and enable to the Deceive user to alter their status directly from the in-game chat interface. This functionality, implemented in MainController.cs under the HandleChatMessage method, was previously undocumented.

The README.md has been updated in this pull request to explain this functionality.