(PEP8) Reformatting, adding README and additional introductory material to the program

I reformatted/cleaned the code a bit, making it PEP8 conform. There are still some TODOs (like unused/undefined variables) that I also added in the code and that can be worked on later. I double checked after the reformatting that the csv files that are output by example.py are exactly the same and I can confirm this is the case. Thus I am confident the formatting does not interfere with the program itself.

I also added a README.md. Of course, it is just a preliminary version and we can always add/remove stuff in later merge requests. I also added the Introduction.ipynb file that you have already seen on colab. I think it is a nice and illustrative example of how one can use the different analysis and plotting capabilities of the program. Also here, we can of course in a later merge request add/remove things as we like.