Add basic pre-commit config

[hugovk]

More can be added as required (see https://pre-commit.com/hooks.html), but this adds a basic pre-commit config file to stop the check erroring PRs (e.g. https://github.com/jazzband/django-embed-video/pull/160):

[hramezani]

@hugovk I created a new PR with your pre-commit config and a new commit to fix the failing test. I close this PR