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": "535ffa28-6148-4000-8cd0-ad0d0f8081f4",
    "type": "playbook_tasks",
    "attributes": {
      "playbook_id": "3f69392b-1ca2-493e-8cb8-59806316cc8b",
      "task": "New task",
      "description": "New task description",
      "position": 1,
      "created_at": "2026-01-15T10:34:39.642-08:00",
      "updated_at": "2026-01-15T10:34:39.642-08:00"
    }
  }
}