Docstrings

[okenreed]

Added and improved docstrings for all functions aside from main

[progval]

Hi,

You included a lot of unrelated changes, please send a new PR without these or rebase this PR.

A few other changes that you should do:

• Keep the line break before titles such at "Parameters" or "Returns", they make things more readable.
• Please fix the alignment of docstring lines, they look almost random
• Fix "W - Dec x speed" and "S - Inc x speed" and the two other ones, they are wrong (these keys change speed according to the player's orientation)
• If a longer name does not give more info, keep the short name. eg. y always means height, so yHeight is redundant.
• Use snake_case for variable names