Setup Github action and co

[Carreau]

• Github action
• Pre-commits
  • black/ruff
  • mypy

[agriyakhetarpal]

A link checker would be helpful to add – though it can only validate if a link exists, and not whether it serves as an inventory, it would still be good to check for 404s from time to time. Lychee is a strong and robust candidate and is quite fast as well.

(Let me know if you want me to do this)

[Carreau]

The test suite does a pytest head request to check that the obj.inv exists.
We could, and it would be great to check that the obj.inv are valid. I think the tool posted in #2 could help with that.

[agriyakhetarpal]

Ah, in that case the test suite is better to use, then.