- Replace the pre-commit try-repo template. The only repo that's using
  it (now that all other repos have been archived) is this. The point of
the template is lost when there's just 1 project using it.
- Install Terraform for the relevant hooks.

- Add the hooks package.
- Refactor and fix the bulk_check function.

To test some of the hooks with pre-commit try-repo.

- A bunch of hooks, some copied from previous repos, some improvements
  on previous attempts, some new.
- README, CI, etc.
- A Python utilities module for helping with Python hooks.