Created pre-commit hook

[DiddiZ]

Hello, for integrating the formatting into a DevOps toolstack it is helpful to run the formatter via pre-commit. When this gets merged, this repo can be added to the list of supported pre-commit hooks.

I needed to change the structure to a package and adapt the CLI a bit. These changes probably break the vscode plugin, this needs to be checked.

[vasner]

Super useful PR! Please continue!