Require doc strings

[obycode]

Following up on @Acaccia's comment in my PR, I agree we should enforce the docstrings. It's probably a good idea to require them on private functions too. It looks like rustc supports #![warn(missing_docs)] to warn on public items missing docs. I also see these options in clippy that seem like a good idea to enable:

• missing_docs_in_private_items
• missing_panics_doc
• undocumented_unsafe_blocks

Once this is enabled, we should also utilize GitHub docs to generate and publish the docs with each push to main.