The correct snapshot URL

Hi,

Thank you very much for the blog post explaining everything and this repo showing exactly how to communicate with the camera. It helped me automate my camera in some AI projects that I'm experimenting with.

I managed to reverse engineer the Android app and realised that the correct snapshot URL is `/v1/snapshot` where the `gatewayUrl` is in the dev-config response.

The snapshot API instructs the camera to take a snapshot and here is the response (no image is sent to the caller):

```json
{
"status": "ok",
"code": 0,
"message": "",
"result": {
"value": true
}
}
```

Cheers,
Alan