Mermaid diagrams

You can include Mermaid diagrams using a ```mermaid code fence.

Example input:

```mermaid
flowchart LR
    Parse(Read documents) --> Read(Read pass)
    Read --> Write(Write pass)
    Write -->|If configured| Read
    Write --> Output
```

Example output:

flowchart LR
    Parse(Read documents) --> Read(Read pass)
    Read --> Write(Write pass)
    Write -->|If configured| Read
    Write --> Output