Retrieves a heartbeat

curl --request GET \
  --url https://api.rootly.com/v1/heartbeats/{id} \
  --header 'Authorization: Bearer <token>'

{
  "data": {
    "id": "f260f299-0af1-4825-b605-1f745cd089ec",
    "type": "heartbeats",
    "attributes": {
      "slug": "consectetur-nulla-molestiae-ipsa",
      "name": "Consectetur nulla molestiae ipsa.",
      "description": "Magnam dolor et quas.",
      "alert_summary": "API is down",
      "alert_urgency_id": "bd0602c4-1fd5-4ec0-935d-d37936b54910",
      "interval": 6,
      "interval_unit": "minutes",
      "notification_target_id": "177",
      "notification_target_type": "User",
      "ping_url": "http://localhost:3001/v1/heartbeats/f260f299-0af1-4825-b605-1f745cd089ec/ping",
      "secret": "heartbeat_35562a10c920d2404e12357ca549354d98bba4aa0ba181f12f73688d40e3211a",
      "last_pinged_at": null,
      "expires_at": null,
      "enabled": false,
      "status": "waiting",
      "updated_at": "2025-09-03T02:21:20.028-07:00",
      "created_at": "2025-09-03T02:21:20.028-07:00"
    }
  }
}