Wheels should also be uploaded to PyPI

[anders-kiaer]

The README instructions currently only tell the user to create source distributions to upload to PyPI.

wheels are the preferred way to install from PyPI - while source distribution is used as backup by pip if no matching wheel exists.

More information:

• https://packaging.python.org/guides/distributing-packages-using-setuptools/#wheels
• https://pythonwheels.com/