Co-authored-by: Greg Lucas <greg.m.lucas@gmail.com>

Co-authored-by: Greg Lucas <greg.m.lucas@gmail.com>

Looks like it was rendering as definition list due to the extra indenting.

Co-authored-by: Oscar Gustafsson <oscar.gustafsson@gmail.com>

…ecations

Deprecate functions in backends

Fix ps export of colored hatches with no linewidth

Use repr in error messages

DOC: Add links to explicit vs implicit API everywhere "OO" is used

* Update pre-commit hooks:
   - https://github.com/pre-commit/pre-commit-hooks: v4.0.1 → v4.2.0
   - https://github.com/pycqa/flake8: v3.9.2 → v4.0.1

This is being applied manually and not waiting for pre-commit.ci to
apply it as pre-commit.ci hasn't been turned on yet since these
hooks were introduced in PR 21583.

Add a git blame ignore-revs file to automatically ignore commits listed
in it from the blame view on GitHub. Include in it style changes added by
pre-commit hooks which touch multiple files.

To ignore the commits in the .git-blame-ignore-revs when running `git blame`
locally run: `git blame --ignore-revs-file .git-blame-ignore-revs`.

c.f.:
* https://git-scm.com/docs/git-blame#Documentation/git-blame.txt---ignore-revs-fileltfilegt
* https://docs.github.com/en/repositories/working-with-files/using-files/viewing-a-file#ignore-commits-in-the-blame-view

Add instructions to the devs on how to manually run pre-commit hooks, both for
all the hooks, and for individual hook ids. Example:
`pre-commit run flake8 --all-files`

Also use the 'python -m pip' pattern to be consistent with the rest of the docs.