Use the README file as the docs on PYPI

[HanslettTheDev]

Summary

This PR aims to provide a means for pyafipws to use the README.md file to be used as it's documentation when deployed to pypi.

Checklist

• Classes, Variables, function and methods logic ok
• Comments written explaining what the code does
• All python code is PEP8 compliant (run black .)
• No lint issues (run flake8)

Manual test evidence

Here is evidence from twine when checking the packages in the dist/* folder

[reingart]

Thanks!

For the record, there was an error with pathlib.Path as it is not in all python 2.7 installations (but now it should work with just open)

Eventually we should get rid of this setup code at all with pyproject.toml