Added homework files

What was new to me was how precisely we went through the different

states of a file. As a programmer, all I cared about was pushing a piece

of code from one place to another. I learned about what you prefer as

experienced developers. What was unclear to me before were differences

between commands that seemed to do the same thing.

   75  cd mastering-git/

   76  ls

   77  cd class3_homework

   78  ls

   79  touch 536480.txt

   80  touch 536480_commands.txt

   81  git status

   82  git switch -c hw02

   83  git status

   84  vim 536480.txt

   85  history > 536480_commands.txt