MermaidJS now fully supported

You can now use MermaidJS, which is a diagramming and charting tool that renders Markdown-inspired text definitions to create diagrams dynamically, anywhere you use Markdown in CoCalc: text between code cells in Jupyter notebooks, whiteboards, slideshows, Markdown files, etc. Just put the mermaid diagram description in a fenced code block, like this:

```mermaid
block-beta
columns 1
db(("DB"))
blockArrowId6<["&nbsp;&nbsp;&nbsp;"]>(down)
block:ID
A
B["A wide one in the middle"]
C
end
space
D
ID --> D
C --> D
style B fill:#969,stroke:#333,stroke-width:4px
```

and it will get rendered like this:

block-beta
columns 1
db(("DB"))
blockArrowId6<["&nbsp;&nbsp;&nbsp;"]>(down)
block:ID
A
B["A wide one in the middle"]
C
end
space
D
ID --> D
C --> D
style B fill:#969,stroke:#333,stroke-width:4px

Using Mermaid in exactly this way is also fully supported in JupyterLab and on GitHub. Moreover, if you publish documents on the CoCalc share server, Mermaid also gets rendered properly, e.g., see these examples: