Add pre-commit hooks

[wwuck]

Add two pre-commit hooks, one with all dependencies included

Fixes #39

[abravalheri]

Thank you very much @wwuck. How about we just add the one with .[all]? I think validate-pyproject-minimal would have some problems due to the missing tomli dependency (I left it out of the default set of dependencies because most of the libraries related to packaging vendor their own version of toml, e.g. setuptools).

(I think pre-commit wraps each hook in its own virtual environment, right? So there would be no problems with collisions).

[wwuck]

Ok thanks for the review. I've removed the minimal hook.