Move documentation from MKdocs material

```
$ mkdocs serve

 │ ⚠ WARNING – MkDocs 2.0 is incompatible with Material for MkDocs
 │
 │   MkDocs 1.x is unmaintained. We recommend switching to Zensical, our
 │   new static site generator, as soon as possible. We're providing an
 │   analysis of the situation in this article:
 │
 │   https://squidfunk.github.io/mkdocs-material/blog/2026/02/18/mkdocs-2.0/
```