Move to Jazzband 🎷

[sarahboyce]

As per this discussion: #28 (comment)

We're going to try to tranfer ownership of this project to Jazzband.

Guidelines: https://jazzband.co/about/guidelines

• Viability
  Not a POC or a toy, an established projects with a history of outside contributions that seeks more maintainers ✅
  Agreement from the previous maintainer(s) see: Update to Python 3.8+ and Django 3.2+ #28 (comment)

• Documentation
  End user documentation: https://django-push.readthedocs.io/en/latest/
  Contributor docs exist and all other technical documentation can be added if needed.

• Tests
  Using tox and GitHub actions added in this PR: Update to Python 3.8+ and Django 3.2+ #28

• Conduct
  Agreed and added here: Move to Jazzband prep work 🎷 #30

• Contributor Guidelines
  CONTRIBUTING.rst added here: Move to Jazzband prep work 🎷 #30

• Badges
  Added here: Move to Jazzband prep work 🎷 #30

[sarahboyce]

Was given advice to create an issue in the help repo: jazzband/help#351