Issue with rendering the course

If we try to render the course to preview how our added content looks like, it throws the following error
```bash
sarthak@kde:~/Desktop/computer-vision-course$ doc-builder preview computer-vision-course chapters/ --not_python_module
Initial build docs for computer-vision-course chapters/ /tmp/tmp0uqdjoxf/computer-vision-course/main/en
Building the MDX files: 100%|███████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████| 29/29 [00:00<00:00, 1288.27it/s]
Traceback (most recent call last):
File "/home/sarthak/anaconda3/bin/doc-builder", line 8, in
sys.exit(main())
File "/home/sarthak/anaconda3/lib/python3.9/site-packages/doc_builder/commands/doc_builder_cli.py", line 47, in main
args.func(args)
File "/home/sarthak/anaconda3/lib/python3.9/site-packages/doc_builder/commands/preview.py", line 171, in preview_command
source_files_mapping = build_doc(
File "/home/sarthak/anaconda3/lib/python3.9/site-packages/doc_builder/build_doc.py", line 405, in build_doc
sphinx_refs = check_toc_integrity(doc_folder, output_dir)
File "/home/sarthak/anaconda3/lib/python3.9/site-packages/doc_builder/build_doc.py", line 460, in check_toc_integrity
raise RuntimeError(
RuntimeError: The following files are not present in the table of contents:
- en/Unit 5 - Generative Models/variational_autoencoders
- en/Unit 5 - Generative Models/README
- en/Unit 11 - Zero Shot Computer Vision/README
- en/Unit 2 - Convolutional Neural Networks/README
- en/Unit 1 - Fundamentals/README
- en/Unit 8 - 3D Vision, Scene Rendering and Reconstruction/README
- en/Unit 4 - Mulitmodal Models/README
- en/Unit 9 - Model Optimization/README
- en/Unit 6 - Basic CV Tasks/README
- en/Unit 7 - Video and Video Processing/README
- en/Unit 13 - Outlook/README
- en/Unit 3 - Vision Transformers/README
- en/Unit 12 - Ethics and Biases/README
- en/Unit 10 - Synthetic Data Creation/README
Add them to chapters/_toctree.yml.
```

**Explanation:** This is because there have been README files added to each chapter. However, these README files are not present in the `_toctree.yml`.

**Why it's important:** Being able to render the course locally is important as it can give us a rough overview of how the content looks like.

**Possible solutions could be:**
* Remove the README files for the time being
* Add them to the toctree and also making sure that if anyone adds any chapter contents they also update the toctree making it easier for others to render the course

Open for discussion from other members :v: