Apply ruff formatting to all docstrings

[dfm]

I used a combination of ruff's --fix option and manual editing to get all the doctrings to the be a little more consistent in formatting. This is a huge PR, but the only changes are to docstrings, so maybe that's ok. I'd also be happy to break this up into smaller chunks if that would be better for reviewing.

I've left in the ruff config that I used which means that this lint check would become part of our pre-commit that we run on CI. I don't feel strongly about actually including these checks as part of our pre-commit, and I'd be happy to revert the changes to pyproject.toml, but @jakevdp suggested that it could be useful to try it out for catching at least some doc formatting errors.