For an easy, out of the block, self-hosted experience, allow me to recommend:

Docusaurus.io framework. Why? It's compatible with MermaidJS-- simply run 1 install command, and setup 2 config settings-- shown here: https://docusaurus.io/docs/next/api/themes/@docusaurus/theme...

Docusaurus provides: Docs, Blog, Pages. Via Markdown. And for pages, it even allows basic JSX (reactjs style components).

Lately I've really been enjoying the combination of Docusaurus & Mermaid to document my personal projects.