Creates an escalation level for an Escalation Policy

curl --request POST \
  --url https://api.rootly.com/v1/escalation_policies/{escalation_policy_id}/escalation_levels \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/vnd.api+json' \
  --data '
{
  "data": {
    "attributes": {
      "position": 123,
      "notification_target_params": [
        {
          "id": "<string>"
        }
      ],
      "delay": 123,
      "paging_strategy_configuration_strategy": "default",
      "paging_strategy_configuration_schedule_strategy": "on_call_only",
      "escalation_policy_path_id": "<string>"
    }
  }
}
'

{
  "data": {
    "id": "<string>",
    "attributes": {
      "escalation_policy_id": "<string>",
      "delay": 123,
      "position": 123,
      "notification_target_params": [
        {
          "id": "<string>"
        }
      ],
      "escalation_policy_path_id": "<string>",
      "paging_strategy_configuration_strategy": "default",
      "paging_strategy_configuration_schedule_strategy": "on_call_only",
      "created_at": "<string>",
      "updated_at": "<string>"
    }
  },
  "included": [
    {
      "id": "<string>",
      "type": "<string>",
      "attributes": {},
      "relationships": {}
    }
  ]
}