Hi,
syntax highlighting isn't working for me. Blocks like


```json
{
  "current_weather": {
    "temperature": 12.4
  },
  "daily": {
    "time": ["2026-02-15", "2026-02-16"],
    "temperature_2m_max": [14.2, 15.0],
    "temperature_2m_min": [5.1, 6.3]
  }
}
```

show withough color. Using the exact same boook source and using
upstream's `cargo install mdbook` binary shows colors as expected.

Cheers,
 -- Guido