Feature request: add mermaid to lua-filters/diagram-generator

[David-Else]

https://mermaid-js.github.io/mermaid/#/

There is a cli app https://github.com/mermaid-js/mermaid-cli available. You just need to npm install @mermaid-js/mermaid-cli and run it using npx. As an example, to process all the files once extracted:

for i in *.mmd; do npx mmdc -i "$i" -o "${i%.*}.png" -b transparent -t forest; done

Would be great to get that included!