Getting mutt 2.x to work with gmail under OAuth2

References:
  1. https://www.redhat.com/sysadmin/mutt-email-oauth2 -- very helpful, I followed these instructions and got it working, though the Google project was set up using instructions from item 2 below.
    I have placed a simple copy of this page here
    After the designated time has elapsed, the gpg key needs to be regenerated using the gpg --gen-key command.
  2. https://luxing.im/mutt-integration-with-gmail-using-oauth/ -- useful information for setting up a project for your Google account and getting credentials and the crucial client_id and client_secret you need to put into the mutt_oauth2.py script
  3. https://howto.cs.uchicago.edu/nix:mutt -- for Microsoft cloud, but some helpful info on using mutt_oauth2.py