Create readthedocs wiki

[robnagler]

• https://docs.readthedocs.com/en/stable/guides/pull-requests.html
• https://docs.readthedocs.com/en/stable/guides/connecting-git-account.html
• https://docs.readthedocs.com/en/stable/guides/setup/git-repo-automatic.html

[robnagler]

Updated https://github.com/radiasoft/pykern/wiki/CreatePythonProject for both readthedocs.org and pypi.org