Write a Haskell function countZeroes that takes a list of
integers as a parameter and returns the number of zeroes contained in
the list. For example, if I called countZeroes [5,0,0,8,0], it
should return 3, since the list contains three zeroes.
countZeroes [] = 0 countZeroes (0:xs) = 1 + countZeroes xs countZeroes (_:xs) = countZeroes xs