Contract the scene to a sphere of radius 2. This is the same contraction used in MipNeRF 360.
Add mipnerf 360 graph and config. It currently doesn't contain the other advancements made in the paper (sample proposal network, regularizers)
* renaming dataloader to data. adding some dataloader classes
* restructuring configs
* fixed instant ngp tcnn direction rescaling
* working through test cases
* black and lint and tests