I've done that course, and some these files look very similar to the boilerplate code that you have to modify/complete for the weekly coursework. Comments seem to have been removed and some refomatting done.

Edit: As jszymborski points out, there an attribution of the source in the readme.md.

I've put my comments deeper in this thread. But just in case I'll also summarize them here. The links to the Andrew Ng course is on every README of the repo: on top of the main README.md and in the "References" section of each internal README.md. Regarding the changes to the original course's code the following has been changes/added: code and comments were reformatted for better reading (in my opinion), code has also been split differently than in the course: I was trying to distinguish some similarities between the algorithms like separate hypotheis() function, separate gradient_descent_step() function and so on. The most significant changes have been made to the neural-network section since it now supports multiple internal layers of different size for the neural network. The course's version of the code supported only one internal layer. Also README file contains additional images (sometimes animations) and definitions for additional learning experience.