Move the training material out of the top-level readme #117
Description
Suggest using the top-level readme in a more conventional way, to describe what the repo is and how to use it. Then put the actual training course in a separate file/files.
My suggested structure for the readme would be similar to that in the introduction to Git repo which I worked on previously.
Note the current introductory paragraphs (for this repo) are a mix of what the repo is, and the beginning of the course introduction ("Knowing how to write your own functions is a great skill..."). Suggest separating these out.