5.2.0 Initial CS2 support

Initial CS2 support (shaders/maps/models)
Better physics import(all physics types are supported, imported as meshes)
Various bug fixes and stability improvements

What's Changed

• Added few controls for prop/entity import by @REDxEYE in #221
• Added usage information to README.md by @redstonedash in #226

New Contributors

• @redstonedash made their first contribution in #226

Full Changelog: 5.1.0...5.2.0