Merman Font Overrides
class MermanFontOverrides
Merman font families that the portable com.jetbrains.kmermaid.MermaidTheme.fontFamily does not reach.
Every value is a CSS font-family list such as Inter, sans-serif. Diagrams that read only the theme font (flowchart, class, state, sequence, ER, mindmap, timeline and others) need no entry here. When the theme sets a font family, C4 and journey families default to it instead of Mermaid's "Open Sans", sans-serif.