Add documentation for building for SDK 2013

[misyltoad]

Should be a simple write up, tl;dr is just to clone the Mini SDK 2013 from my repos, then clone vphysics-jolt inside the mp/src folder, install the registry hack and generate the projects.

Should probably be on a wiki page or something. If someone external does this they can just do this on a fork and it can be copied over.

[Bagellll]

I'll get started on something. I was able to build on both windows and linux so I'll document the entire process.

[maksw2]

what about the normal sdk?