Missing rule proprety on .isHoliday()

 Property "rule" is missing on returned object of .isHoliday() method.

Result example for France:
```
[
    {
        "date": "2025-08-15 00:00:00",
        "start": "2025-08-14T22:00:00.000Z",
        "end": "2025-08-15T22:00:00.000Z",
        "name": "Assomption",
        "type": "public"
    }
]
```