mermaid-syntax

Mermaid syntax reference for writing or fixing a diagram in an artefact: flowchart, sequence, class, state, ER, Gantt, C4, mindmap, timeline and the other diagram types, node shapes, styling, theming, and why a diagram fails to render. Not needed for PlantUML (plantuml-syntax), or when the request is for a governed diagram artefact with document control, which $arckit-diagram produces.