feat: Add list comprehension in list tutorial

[varian97]

Add list comprehension section in List and Tuple Tutorial

[Akuli]

Introducing list comprehensions in the list and tuple tutorial seems like a good idea. Maybe also show an example that does the same thing by filling in a list with a loop, and mention that list comprehensions are just a shorter way to write a loop like that?

numbers_squared = [] for number in numbers: numbers_squared.append(number**2) 

[varian97]

Thanks for the suggestion, I have edited the tutorial with the example given.

[Akuli]

Your commits are now in the tutorial, 93a00c2 and 52073d8. Don't know why they don't show up on github. Also I don't know why I didn't do anything about python-tutorial pull requests in about a year.