Add elk Renderer Support to Mermaid Diagram as a Layout Engine

The elk rendering engine is not available in Mermaid Diagrams in Outline. This is typically selected by prepending the following into the Mermaid code:


Information about how to select the elk rendering engine in Mermaid is available at

It appears that the package layout-elk must added to the Outline source tree and then imported per the directions available at

This would aid greatly when developing complex diagrams with Mermaid in Outline.