input: Write a python function to join a list of strings with a given delimiter.
  assert join_list_str(["Apple", "Orange", "Mango"], ",") == "Apple,Orange,Mango"
  assert join_list_str(["Hello", "world"], " ") == "Hello world"
  assert join_list_str(["a", "b", "c"], "-") == "a-b-c"
output: def join_list_str(lst, delimiter):
      return delimiter.join(lst)