text: Title: [BUG] Extended PageContent documentation wrong
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  ## Description
  
  I am attempting to extend the `PageContent` model following the example provided in the official django CMS documentation: [Extending PageContent Model](https://docs.django-cms.org/en/latest/how_to/18-extending_page_contents.html#pagecontent-model-extension-example). While everything works as expected, I am facing an issue with retrieving the page content extension in a template.
  
  ## Steps to reproduce
  
  Steps to reproduce the behavior:
  1. Follow the steps to extend the `PageContent` model as per the documentation linked above.
  2. Add custom fields to the `PageContent` extension model.
  3. Try to render the extended content in a template using the provided example.
  4. Notice that the extended content is not being retrieved or rendered as expected in the template.
  
  ## Expected behaviour
  
  The extended content fields added to the `PageContent` model should be accessible in the template, allowing for proper rendering of the extended fields' data.
  
  ## Actual behaviour
  
  While the `PageContent` model extension works correctly in the admin interface, the extended content is not being retrieved in the template. The extended fields do not display or render as expected.
  
  ## Screenshots
  
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  _No screenshots available for this issue._
  
  ## Additional information (CMS/Python/Django versions)
  
  - Django CMS version: 4.1.2
  - Python version: 3.11
  - Django version: 4.2.8
  - Environment: local development
  - Logs: No relevant logs were generated during the issue.
  
  ## Do you want to help fix this issue?
  
  * [ ] Yes, I want to help fix this issue and I will join the channel #pr-reviews on [the Discord Server](https://discord-pr-review-channel.django-cms.org) to confirm with the community that a PR is welcome.
  * [x] No, I only want to report the issue.
  