Changing representation of base case to help understand form of recursion

[bharatagarwal]

This is an opinionated suggestion, feel free to not merge.

I think the fact that height == 0 is the base case for the function is implicit, and maps slightly separately to the way the text talks about the base case.

By making a return explicit when height == 0, it helps to visualise how the call stack is being used.

[robot-dreams]

I agree this is a bit confusing. Is it also worth changing the text, which currently says "A tower of one disk will be our base case." (the base case should be a tower of zero disks)?

Alternatively, should we have something like:

if height == 1:
    move_disk(from_pole, to_pole)
else:
    move_tower(...)
    move_disk(...)
    move_tower(...)