Keeping track of my progress on Duolingo.

About the .keep files: git doesn't commit empty folders, so when I want an empty folder to be commited to GitHub I add an empty file to the folder.

As 2021-12-04 'points_rank' was no longer available from Duolingo API. Had to remove all references to 'points_rank' from code. The package duolingo-api from pypi also no longer worked, so downloaded the code from Github. Renamed the file duolingo.py to duolingoapi.py, removed references to 'points_rank' and included it in my repository (for now).