Add pre-commit configuration

[redsun82]

pre-commit is a framework for easy set-up of pre-commit hooks.

This adds configuration for it to run:

• ts compilation
• ts linting
• pr-checks synchronization

The latter required the sync.py to be callable from the project root.

pre-commit can be enabled with

python3 -m pip install pre-commit
pre-commit install

Merge / deployment checklist

• Confirm this change is backwards compatible with existing workflows.
• Confirm the readme has been updated if necessary.
• Confirm the changelog has been updated if necessary.

[henrymercer]

This looks good. It isn't for me, as it makes committing take too long, but I'm happy to approve it.

[redsun82]

This looks good. It isn't for me, as it makes committing take too long, but I'm happy to approve it.

yeah, it's true I was a bit hesitant about the linting check (the other two are pretty much instant if compilation was already done). On the other hand for me that I don't work so often here, I was already bitten by committing something not passing all three of the checks 😅

FYI there is a way to tweak the configuration locally.