Add .pre-commit-config.yaml

[mattwthompson]

Implements a part of #1039

• Update developer docs

[codecov]

Codecov Report

Attention: Patch coverage is 54.16667% with 33 lines in your changes missing coverage. Please review.

Project coverage is 86.86%. Comparing base (e70c266) to head (0c3457b).
Report is 106 commits behind head on master.

Additional details and impacted files

[mattwthompson]

Taking this comment #1022 (comment) and a general support elsewhere as approval.

I had already added the bot while working on that PR, so it'll be used to see if this passes.

[mattwthompson]

In principle this replaces .github/workflows/lint.yaml but I'll leave that be for now in case one catches something the other misses / in order to gain some trust.