Creates an incident event service

curl --request POST \
  --url https://api.rootly.com/v1/events/{incident_event_id}/services \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/vnd.api+json' \
  --data '{
  "data": {
    "type": "incident_event_services",
    "attributes": {
      "incident_event_id": "<string>",
      "service_id": "<string>",
      "status": "operational"
    }
  }
}'

{
  "data": {
    "id": "6f050017-dd9b-4a3e-b20f-858efd17ad9d",
    "type": "incident_event_services",
    "attributes": {
      "incident_event_id": "f80d7f0a-a783-42a6-82e6-b25d2763875a",
      "service_id": "0b95bb49-d40b-4123-ade2-c7099481c7cc",
      "status": "partial_outage"
    }
  }
}