Creates a heartbeat

curl --request POST \
  --url https://api.rootly.com/v1/heartbeats \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/vnd.api+json' \
  --data '{
  "data": {
    "type": "heartbeats",
    "attributes": {
      "name": "<string>",
      "description": "<string>",
      "alert_summary": "<string>",
      "alert_urgency_id": "<string>",
      "interval": 123,
      "interval_unit": "seconds",
      "notification_target_id": "<string>",
      "notification_target_type": "User",
      "enabled": true
    }
  }
}'

{
  "data": {
    "id": "efa1009d-a679-4750-b986-b418873725d4",
    "type": "heartbeats",
    "attributes": {
      "slug": "api",
      "name": "API",
      "description": "This is a description",
      "alert_summary": "API is down",
      "alert_urgency_id": "fec927ba-0399-4031-8519-a9ae6f798a95",
      "interval": 1,
      "interval_unit": "minutes",
      "notification_target_id": "159",
      "notification_target_type": "User",
      "ping_url": "http://localhost:3001/v1/heartbeats/efa1009d-a679-4750-b986-b418873725d4/ping",
      "secret": "heartbeat_c86a6767869e48366b33419c4c27aea639b26d3954a910769756eeb7cba4e03b",
      "last_pinged_at": null,
      "expires_at": null,
      "enabled": false,
      "status": "waiting",
      "updated_at": "2025-08-07T22:37:01.392-07:00",
      "created_at": "2025-08-07T22:37:01.392-07:00"
    }
  }
}