Rendering extensions

Markzen extends standard markup through fenced code blocks. The language tag right after the opening triple backticks decides how the block renders: a tag Markzen recognises as an extension draws a live figure instead of showing the code.

For example, this source:

```mermaid
graph LR
  A --> B --> C
```

renders as a live flowchart, not a code listing — and it stays a flowchart in PDF and HTML exports too.

Thirty extensions are built in, by category:

Category	Extensions
Diagrams	Mermaid, Graphviz, Cytoscape, Markmap, Timeline, Nomnoml, PlantUML, DBML, Railroad Diagrams, Bytefield, WaveDrom
Charts	Chart.js, Vega-Lite, ECharts, Plotly, function-plot, JSXGraph
Math	KaTeX, AsciiMath
Music	ABC Notation, VexFlow, VexChords, ChordPro, MusicXML
Other	Pseudocode, Tabulator, QR Code, SMILES, Chess, Go Board

Each extension has its own language tag (mermaid, chartjs, katex, abc, chess, …). You can mix as many as you like with ordinary prose in a single document — they all render together, and all survive export.