V Pipeline: an open-source, vertex-based, uber shader and Blender addon

To do:

• include pipeline support for emission textures and decals
• add a 3rd UV channel and map to CUSTOM0. xy corresponds to UV3
• compile demo that includes light baking - this could be a problem since Godot expects UV2 to be free in the light-baking process
• consider GDextension/engine mod to fix light baking issue