Add pre-commit (fixes #32 #33)

Decided to try out ruff. Rules can be found here https://docs.astral.sh/ruff/rules/.

Right now we have:

• E: pycodestyle (Error: https://docs.astral.sh/ruff/rules/#pycodestyle-e-w)
• F: Pyflakes (https://docs.astral.sh/ruff/rules/#pyflakes-f)
• W: pycodestyle (Warning: https://docs.astral.sh/ruff/rules/#warning-w)
• I: isort (https://docs.astral.sh/ruff/rules/#isort-i)
• N: pep8-naming (https://docs.astral.sh/ruff/rules/#pep8-naming-n)
• D: pydocstyle (https://docs.astral.sh/ruff/rules/#pydocstyle-d)
• C: flake8-comprehensions (https://docs.astral.sh/ruff/rules/#flake8-comprehensions-c4)
• PT: flake8-pytest-style (https://docs.astral.sh/ruff/rules/#flake8-pytest-style-pt)
• INP001: flake8-no-pep420 (https://docs.astral.sh/ruff/rules/#flake8-no-pep420-inp)
• T20: flake8-print (https://docs.astral.sh/ruff/rules/#flake8-print-t20)
• ARG: flake8-unused-arguments (https://docs.astral.sh/ruff/rules/#flake8-unused-arguments-arg)
• ERA001: eradicate (https://docs.astral.sh/ruff/rules/#eradicate-era)
• NPY: NumPy-specific rules (https://docs.astral.sh/ruff/rules/#numpy-specific-rules-npy)

Rulest to consider later: refurb (FURB)

Most changes in the code is because of mypy. I have made some basic testing to make sure it still works.