Adjusted terrain atlas textures import settings
Force disabled PVT via script and changed default terrain material to Procedural-ATLAS; updated TerrainGenerator prefab
Updated layer masking to handle 4-channel specular
Changed some shaders to half precision across the board for some low-end love
Added atlas path to "Rust/Standard Procedural Terrain" in order to match the shader used in the menu scene
Deleted some seemengly unused shaders that weren't compiling