[V2] Adding more refence docs

[onel]

Great project.

I see big parts of the codebase are commented but some are not.
Would you be interested in some PRs documenting more of it?
I'm willing to help with that.

[PromtEngineer]

that will be a great help. thanks

[onel]

Awesome. I'll go over the parts that need more docs and come back with some updates

[onel]

Sorry it took a bit to get to this.
I've opened the first PR with a first batch of files.
LMK what you think.

I'm not sure about the style of inline docs that's best for the project.
I went with the google style (that has Args:, Returns: etc.), LMK with another style should be used.

I see some of the files use the "simple" style, where the docs only explain the purpose of the method / class without explaining, the params, returns, raises, etc.
What is preferred?