input: Write a python function to group elements of a list into sublists of a given size.
  assert group_list([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 3) == [[1, 2, 3], [4, 5, 6], [7, 8, 9], [10]]
  assert group_list([10, 20, 30, 40, 50, 60], 2) == [[10, 20], [30, 40], [50, 60]]
  assert group_list([5, 15, 25, 35, 45], 1) == [[5], [15], [25], [35], [45]]
output: def group_list(lst, size):
      return [lst[i:i + size] for i in range(0, len(lst), size)]