Fix latest mkdocs-material

[tfc]

Contribution checklist (recommended but not always applicable/required):

• There's an automated test for this change
• Commit messages or code include references to related issues or PRs (including third parties)
• Commit messages are conventional - examples from the log include "feat: add changelog files to fixup hook", "fix(contourpy): allow wheel usage", and "test: add sqlalchemy2 test"

[tfc]

@adisbladis had some formatting errors that are fixed now. It's also rebased as there were a few changes that became redundant with the latest commits.