前文提要: https://www.v2ex.com/t/532704#reply10
图表用的是 Mermaid.js
GitHub: https://github.com/lyricat/code-knack
DEMO: https://lyricat.github.io/code-knack/demo/#
效果如下:

语法很简单,
<pre>
<code class="language-mermaid,autorun">
graph TD
A[Christmas] -->|Get money| B(Go shopping)
B --> C{Let me think}
C -->|One1| D[Laptop]
C -->|Two| E[iPhone]
C -->|Two| E[iPhone]
C -->|Two| E[iPhone]
C -->|Three| F[fa:fa-car Car]
</code>
</pre>