Transition from mkdocs-material to Zensical

[xmfcx]

Blog post: https://squidfunk.github.io/mkdocs-material/blog/2025/11/05/zensical/ (It is from 20 days ago, 2025-11-05)

We should first move from mkdocs-material 9.1.20 to 9.7.0. - It seems we are already on 9.7.0 ✅

This is the last release of Material for MkDocs that will receive new features. Going forward, the Material for MkDocs team focuses on Zensical, a next-gen static site generator built from first principles. We will provide critical bug fixes and security updates for Material for MkDocs for 12 months at least.

I think we can transition next year once it becomes stable.