About Source Footsteps and Phys Sounds

This is my first non-local addon, just to see how asset party works. Right now it's missing some surfaces and some sounds may be wrong, but it'll be fixed when i get around to doing it. Only materials with properly set up surfaces will work with this addon. There are a lot of props that have incorrectly set up materials, so they'll just end up using the default surface type. I'll upload the source files somewhere later so you can set up your own content's materials and props with these surface types if you want to so they work properly.