New pre-commit hooks

[victorsevero]

These were the other pre-commit hooks I considered adding to this project a month ago. What are your thoughts?

• pygrep-hooks: enforce that python3.6+ type annotations are used instead of type comments;
• add-trailing-comma: add trailing commas to calls and literals;
• pydocstyle: check compliance with Python docstring conventions;
• absolufy-imports: automatically convert relative imports to absolute;
• cmake-format-precommit: CMake formatting and linting;
• pre-commit-hooks: C/C++ formatting and linting;
• doctoc: generate table of contents for markdown files.

I haven't run them on all files of the repo, I wanted to make this PR as clean as possible at first. Let me know if you think it's a good idea to run them before merging (in case of approval) or if we should open a new PR for that.

EDIT: didn't know that pre-commit was already running for all files in GH Actions. Nice! EDIT²: I decided to remove C/C++ formatting and linting since it seems broken and not maintained anymore. I also removed the pydocstyle since we have so many files with no docs at all (but I'd love to enforce that in the future).

[victorsevero]

Thanks for removing the TOC plugin from pre-commit but could you remove all of the instances that it added to the code in the markdown files

Sorry! I only searched for .MD (uppercase) files when I was reverting these changes. I'll remove that.