kroki for embedded diagrams

[michael-fuchs]

https://kroki.io/ is a service to render diagrams from text. It's a HTTP interface to a number of tools like plantUML. It's also available as OS docker container for self hosting.

The markdown code-blocks can be used for embedded diagrams. When the markdown is rendered kroki is called on the content of such code blocks to render svg-diagrams. The svg-diagrams are inlined into the output html.

Within markdown the type of the diagram is defined at the "language" level, e.g. "diagram-plantuml". The string after "diagram-" has to match the kroki diagram id.

  ```diagram-plantuml
  <some  plantuml markup>
   \```