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": "f9fa3608-e136-423f-b79b-7c5a4c716564",
    "type": "incident_event_services",
    "attributes": {
      "incident_event_id": "bf07100c-301a-42ce-a4fd-46c5a6493ce1",
      "service_id": "043b2d2a-9146-4706-aaae-3503af11e562",
      "status": "partial_outage"
    }
  }
}