Increase Documentation Coverage

[sdtblck]

Some of our code is fairly underdocumented to say the least.

Where possible, it would be good to:

• Add input / output typehints to all functions
• Add docstrings with at least a short description of the function's purpose, and at best a description of the input and output variables as well.
• Integrate torchtyping

[slash-under]

Initial torchtyping integration is occurring in #600