Better Documentation Training Options

[dorofino]

We need better documentation regarding all training options.
Basically, we need to understand when is good to use each of the setting to product a better NeRF

• Train Encoding
• Train Network
• Random Levels
• Train Envmap
• Train Extrinsics
• Train Exposure
• Train distortion

Best
Diego

[stevekm]

Agreed that the docs could use a general over haul. Especially for install guidelines