Write a function that determines whether or not a given string is a palindrome.
A palindrome is a string that is spelled the same both forwards and backwards, usually without considering punctuation or word breaks:
- A car, a man, a maraca.
- Rats live on no evil star.
- Lid off a daffodil.
- Animal loots foliated detail of stool lamina.
- A nut for a jar of tuna.
palindromes('racecar') // true
palindromes('tacos') // false