Honestly github isn't that bad as a wiki. You get versioning, rich markdown, collaboration, commenting, and it can just be markdown, not some proprietary syntax. And editing right in your browser for non-technical folk, get tell them committing = saving. Might have to manually upload images though. But I recall github supports mermaid diagrams [1].

[1]: https://docs.github.com/en/get-started/writing-on-github/wor...