Invalid URL / File Path Protocol

Just opening this library and finding this bug - figured I would report it.

```json
{
  "type": "url",
  "value": "file:1:2",
  "isLink": true,
  "href": "file:1:2",
  "start": 91,
  "end": 99
}
```

Cheers.

ps; tbh I actually need this exact match lol - tho I do believe it is not valid.