Creates a playbook task

curl --request POST \
  --url https://api.rootly.com/v1/playbooks/{playbook_id}/playbook_tasks \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/vnd.api+json' \
  --data '
{
  "data": {
    "type": "playbook_tasks",
    "attributes": {
      "task": "<string>",
      "description": "<string>",
      "position": 123
    }
  }
}
'

{
  "data": {
    "id": "e809d5a5-f35f-4329-90a0-7c38043a424f",
    "type": "playbook_tasks",
    "attributes": {
      "playbook_id": "fb9ce91b-77bf-4052-92d8-1d9133e72d4b",
      "task": "New task",
      "description": "New task description",
      "position": 1,
      "created_at": "2025-12-05T09:06:04.673-08:00",
      "updated_at": "2025-12-05T09:06:04.673-08:00"
    }
  }
}