input: Write a function to perform linear search on a list of strings.
  assert linearSearch(['school', 'hospital', 'bookstore', 'mall', 'theatre'], 'mall') == 3
  assert linearSearch(['school', 'hospital', 'bookstore', 'mall', 'theatre'], 'theatre') == 4
  assert linearSearch(['school', 'hospital', 'bookstore', 'mall', 'theatre'], 'grocery') == -1
output: def linearSearch(lst, target):
      for index, value in enumerate(lst):
          if value == target:
              return index
      return -1