chore: maintainership phase 1 tasks

[rgraber]

Description:

Added catalog-info.yml, maintainership status badge in the readme, and a default statement into .github/workflows/upgrade-python-requirements.yml to make it better match the template.

Issue:

https://github.com/openedx/edx-django-utils/issues/255

Reviewers:

• [ ] tag reviewer

Merge checklist:

• [ ] All reviewers approved
• [ ] CI build is green
• [N/A] Version bumped
• [N/A] Changelog record added
• [ ] Documentation updated (not only docstrings)
• [ ] Commits are squashed

Post merge:

• [N/A] Create a tag
• [N/A] Check new version is pushed to PyPi after tag-triggered build is finished.
• [ ] Delete working branch (if not needed anymore)