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": "d4f2896c-29af-411b-90e4-c9421d5aa038",
    "type": "incident_event_services",
    "attributes": {
      "incident_event_id": "2317f5f6-a84a-48d0-af0f-be81412549b3",
      "service_id": "8eedbbc5-2098-43ba-b2ce-bb68e09bcc5f",
      "status": "partial_outage"
    }
  }
}