Update Support Level from Active to Stable

[jeffpaul]

Description of the Change

This PR drops the support level from Active to Stable. There's a similar support forum post on WP.org that attempts to avoid support issues there and instead push folks to GitHub as well as note that bugs and security issues get priority, PRs for enhancements will be considered, but otherwise we intend to test against major WordPress versions only.

How to test the Change

n/a

Changelog Entry

Changed - Support Level from Active to Stable.

Credits

Props @jeffpaul.

Checklist:

• [x] I agree to follow this project's Code of Conduct.
• [x] I have updated the documentation accordingly.
• [ ] I have added tests to cover my change.
• [ ] All new and existing tests pass.