Annotate code with docstrings; partial code lint

[jatkinson1000]

Arthur adding docstrings where requested by @jatkinson1000

[raehik]

Rebasing onto main (previously was merging onto documentation branch, which doesn't seem too far away history-wise).

[raehik]

This branch was originally based off #17 . That PR would have probably been better as an issue to avoid branching & merging of subbranches - which is fine and dandy, but adds a layer of Git complexity and GitHub doesn't make merge targets very visible. I suggest we:

1. merge this
2. rebase #17 and merge any changes
3. continue docs/linting work in smaller PRs

I've renamed this PR to clarify the changes it brings.

I've also rebased this to main. @arthurBarthe you'll need to "force pull" this to re-synchronize. This StackOverflow question explains it best:

git checkout arthurdocs # switch to this branch
git fetch --all # get all remote changes
git reset --hard origin/arthurdocs # change your local arthurdocs to use remote arthurdocs

[raehik]

I'll do the above, since we're not to lose any history, just have some messy branches for a minute.