[billsix]

I teach a class on computer graphics, where I want to embed my working source code into my web based explanations, so perhaps the following could help you

I have my source code in one directory, and in another I use Sphinx to make the documentation. In the documentation, I reference certain sections of code, which you can do by line number, or you can do by some pattern to begin and end.

Since I control all my source code, I put in comments with certain flags for regions of code.

I can then reference said section of code as follows

  .. literalinclude:: ../../src/demo06/demo.py
     :language: python
     :start-after: doc-region-begin define uniform scale
     :end-before: doc-region-end define uniform scale
     :linenos:
     :lineno-match:
     :caption: src/demo06/demo.py

https://github.com/billsix/modelviewprojection/blob/master/b...

The generated book is here https://billsix.github.io/modelviewprojection/

For your purposes, using a third party's code, I would make a new git repository, and copy the current status of their code in, I would then annotate the sections that I want to with comments, And then generate the documentation using Sphinx, referencing you annotations of their code