py.typed needed for PEP 561 compatibility

Hi, to be able to use the type hints with mypy, you have to add a py.typed file to the package to make it PEP 561 compatible. I tried to fork the project and tried multiple things to get py.typed into the built package, but somehow I can't do it. I have also not worked with setuptools for a long time. https://peps.python.org/pep-0561/ https://blog.whtsky.me/tech/2021/dont-forget-py.typed-for-your-typed-python-package/ https://setuptools.pypa.io/en/latest/userguide/datafiles.html Thank you