curl --request GET \
  --url https://api.open.cx/training/directories/tree \
  --header 'Authorization: Bearer <token>'

{
  "directories": [
    {
      "id": "<string>",
      "name": "<string>",
      "org_id": "<string>",
      "items": [
        {
          "id": "<string>",
          "title": "<string>",
          "content": "<string>",
          "draft_title": "<string>",
          "draft_content": "<string>",
          "is_draft": true,
          "directory_id": "<string>",
          "restricted_to_channels": [],
          "restricted_to_segments": [
            "<string>"
          ],
          "current_version": 123,
          "metadata": {},
          "published_at": "2023-11-07T05:31:56Z",
          "created_at": "2023-11-07T05:31:56Z",
          "updated_at": "2023-11-07T05:31:56Z"
        }
      ]
    }
  ],
  "uncategorized": [
    {
      "id": "<string>",
      "title": "<string>",
      "content": "<string>",
      "draft_title": "<string>",
      "draft_content": "<string>",
      "is_draft": true,
      "directory_id": "<string>",
      "restricted_to_channels": [],
      "restricted_to_segments": [
        "<string>"
      ],
      "current_version": 123,
      "metadata": {},
      "published_at": "2023-11-07T05:31:56Z",
      "created_at": "2023-11-07T05:31:56Z",
      "updated_at": "2023-11-07T05:31:56Z"
    }
  ]
}