input: Write a function to search if any string from a given list of strings matches a user input string. The function should return "String matches" if any match is found, otherwise it should return "String doesn't match".
  assert search_strings(["First", "Second", "Third"], "Second") == "String matches"
  assert search_strings(["First", "Second", "Third"], "Fourth") == "String doesn't match"
  assert search_strings(["First", "Second", "Third"], "FirstSecond") == "String matches"
  assert search_strings([], "Second") == "String doesn't match"
output: def search_strings(string_list, user_input):
      for s in string_list:
          if user_input in s:
              return "String matches"
      return "String doesn't match"