Support mermaid

[BenjaBobs]

Mermaid is a text-to-diagram library that is very useful for writing up flow charts or class diagrams or what not.

Markdown-it has some plugins that add support for the mermaid tag, e.g.

graph TD
    A[Christmas] -->|Get money| B(Go shopping)
    B --> C{Let me think}
    C -->|One| D[Laptop]
    C -->|Two| E[iPhone]
    C -->|Three| F[Car]

Renders to this:

Example: https://mermaidjs.github.io/mermaid-live-editor/

A possible implementation: https://www.npmjs.com/package/markdown-it-mermaid

[vid]

Support for Mermaid would be a Big Deal in this extension for complex projects. Thanks for your consideration.