v0.12 - Official Wagtail 6 support, and drop Wagtail < 5.2

Warning

This release supports Wagtail 5.2+ only.
It also removes the long deprecated MarkdownPanel

What's Changed

• Tidy ups for Wagtail 6.0 by @katdom13 in #139
• Allow customizing tab_length by @bjackson in #136
• Prep release v0.12 by @zerolab in #140
• Various tooling tweaks
• Drop support for Wagtail < 5.2, and the long deprecated MarkdownPanel

New Contributors

• @katdom13 made their first contribution in #139
• @bjackson made their first contribution in #136

Full Changelog: v0.11.1...v0.12.0