Neat, but you can just do this in mermaid too. Taking one of your examples:

  <mermaid>
  flowchart LR

  web([Frontend])

  subgraph platform [Cloud Platform]
    api([API Server])
    db[(Database)]
    api --> db
  end

  web -->|HTTPS| api
  </mermaid>

If you install the latest https://oj-hn.com , you can see it rendered inline here.