Mermaid Diagram with GitLab - jrcloudsolutions/tidbits GitHub Wiki
Mermaid diagrams are JavaScript-based diagramming and charting tool that uses Markdown to create and modify diagrams. You can write text to render diagrams
GitLab natively supports Mermaid diagram, no extensions or GitLab Ruby/UI configurations needed.
There is also a free Mermaid Live Editor app to obtain sample code.