fix: py.typed

[henryiii]

This package is missing a py.typed file, so downstream projects will not
show up in mypy or other type checkers, even though it has nice .pyi
files. This adds a the token file, which will cause mypy to pick it up
and use it. See PEP 0561.

It was also missing the .pyi files from the wheel (noticeable when running
pip install build && python -m build), added include_package_data to
fix that.

Edit: Actually I ran pipx install build && pyproject-build, but that's the same thing.

Closes #318

[henryiii]

This was attempted before in #318, apparently, but the py.typed fix is missing from that, which is quite important.

[codecov-io]

Codecov Report

Merging #347 (0fa383f) into master (3f637db) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #347   +/-   ##
=======================================
  Coverage   89.74%   89.74%           
=======================================
  Files           5        5           
  Lines        1063     1063           
=======================================
  Hits          954      954           
  Misses        109      109           

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[kevinjacobs-progenity]

Some of the type stubs look wrong too. e.g.

def load(f: Union[str, list, IO[str]],
         _dict: Type[MutableMapping[str, Any]] = ...,
         decoder: TomlDecoder = ...) \
         -> MutableMapping[str, Any]: ...

should be

def load(
    f: Union[str, list, IO[str]],
   _dict: Optional[Type[MutableMapping[str, Any]]] = None,
    decoder: Optional[TomlDecoder] = None,
) -> MutableMapping[str, Any]: ...

I'm happy to work on this. Any objects to pushing my updates to this PR or should I open a new one?

[henryiii]

I'm perfectly happy to have pushes (sorry I missed this before!). One of the reasons this may have worked in the past is that typeshed had toml in it (I believe), but that's going away in the future (0.900), so having these would be especially useful soon!

[wimax-grapl]

I too have come across this, would be really nice to get it in (and get out of Typeshed!)

[henryiii]

Tomli and tomllib (in Python 3.11) have replaces this. So closing.