Add more pre-commit linting

[jorisvandenbossche]

The pre-commit linting related commits by @pradyunsg from #514, so those can already be merged separately

[jorisvandenbossche]

@choldgraf I am personally fine with those, you're OK with merging? (as long as pre-commit runs them, I don't care too much which exact linting rules we use :))

[choldgraf]

+1 from me, any objection to using pre-commit.ci ?

[jorisvandenbossche]

Thanks @pradyunsg !

(enabled "rebase and merge" for a moment, to preserve Pradyun's commits)

any objection to using pre-commit.ci ?

I have no experience with it. What does it exactly provide over the current pre-commit running in github actions? Automatic fixing?
(I am not sure if I am in favor of by default running this automatically, IMO it can also give annoying conflicts if commits were added remotely that you don't have locally, and fixing that up is not necessarily a newbie git workflow. I would personally prefer an "on demand" automatic fix)

[choldgraf]

yeah - the main benefit I've found is when people make edits to things directly from the GitHub UI, or where they make edits before remembering to install pre-commit locally. In those cases, if you forgot to do something that pre-commit would have fixed, it is automatically applied to the PR. So most useful for first time contributors or drive-by contributors. Not a huge deal either way but maybe something we can consider if we run into this issue relatively often

[pradyunsg]

FWIW, you can't use pre-commit.ci unless you drop the "local" step that builds things using the yarn-installed environment. :)