rename ex0 to ex3
add ex4 and ex5
add ex6 Strings And Text
add ex7 More Printing
add ex8 Printing,Printing
add ex9 Printing Printing Printing
add ex10 what was that
add ex11 asking questions
add ex12 libraries
add ex13 parameters unpacking variables
add ex14 prompting and passing
add ex15 reading files