Draft: Given a string, return all substrings that are palindromes. By substrings, I mean that you can also remove characters in between, e.g. fobarrbf -> brrb, bab, fof, fbf, faf, frf, bb, brb, etc. (duplicates are allowed)
Draft: Given a string containing only ASCII letters, output it 4 times: once uppercase, once lowercase, once titlecase (all lowercase, first char uppercase), once with the cases swapped. Output in any order
