Commented 2019 code

Even if you don't know Java syntax, there are explanations here for you to get the gist of what is going on -- start by reading the README's. There are also comments (explanations in English) of what is going on -- you can start by focusing on the ones that start and end with /* ! ! ! ! ! ! ! ! ! ! ! ! ! !

Click on the <> Code tab in the top left of your screen, then the folder src/main --> java --> frc/robot