In functions2.rst, explain difference between return and print

[presnick]

When an expression evaluates to a value, including when a function returns a value, there are three things that might happen to the value: -- show it to the user (print) -- use it as part of a more complex expression -- save it for later use, either by assigning to a variable, or adding to a data structure like a list or a dictionary.

Print just shows things to the user. Return makes it available for one of the other two uses.

[aerenchyma]

IIRC this is all set, though if we want to add other textbook things those could be issues too. Can open again if you think I'm incorrect here of course