Add annotations, comments, and docstrings to source.

[jakefrommars64]

Is your feature request related to a problem? Please describe.

Go through the Foam source code and add annotations, comments, and docstrings that describe and detail what each part of the code is and does. Including parameters, potential references, and anything else that would be useful to improve the readability and navigability of the code.

The TypeScript team has already defined a docstring-like documentation standard