I'm not the person you replied to, but for projects I maintain at work we've got a plugin for Confluence called Mark. It allows using Markdown to create Confluence pages, which is useful because the company uses Confluence for some reason. For diagrams (Mermaid, GraphViz, etc.) the source for the diagram is kept with the Markdown & I've got a CI job that generates diagrams & then runs Mark to update Confluence.

It makes it a lot easier to keep the documentation in sync with the code than having to remember to go to Confluence and update things. And avoids the pain of dealing with Atlassian's slow-loading site.