First of all, if you want to know more about ML we recommend you this news: What is Machine Learning?
Regarding the Github project, it discusses the implementation of different ML algorithms from scratch in Python 3.
Celia explains a top find: the Github project to help understand the mathematics behind different ML algorithms, as well as why they work or not depending on the data used. The author started it in order to explain for Linear Regression how different gradients changed, but the project grew gradually. Later, he also wanted to visualise the training process in order to have a better intuition of what exactly happens during the training process. Over time, more algorithms and visualisations have been added.
In the following link you can find out more about the algorithms of the Machine Learning.