Steam Workshop Support for Main Menu Background Image

It'd be really cool if we could change our main menu background with an image of our own choosing or one that's been creating by our community via Steam Workshop.

The pros of this mean that users can create their own custom main menu background or even replace it with just a black screen if they please to do so. Another advantage of this means that the community can come together to share their ideas and thats always a great time when the community comes together to bring an idea to life. Could add some real cool atmosphere.

Could also add a `Background of the Month` contest for users to create the best background for Intruder and have it be featured in an update and some other goodies. Let me know your feedback.