guidebook has built-in support for Mermaid diagrams.
Use a mermaid code block:
```mermaid
graph TD
A[Start] --> B{Decision}
B -->|Yes| C[Do something]
B -->|No| D[Do something else]
C --> E[End]
D --> E
```
If you don't need Mermaid support:
{
"plugins": ["-mermaid-md-adoc"]
}