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": "495a782d-56d6-48dc-a5a5-2f9433d99ff8",
    "type": "incident_event_services",
    "attributes": {
      "incident_event_id": "25115eae-22fc-4256-9089-19d4fb08ee31",
      "service_id": "f1cb158b-5c25-46ef-a85f-a36a55f776f2",
      "status": "partial_outage"
    }
  }
}