input: Write a function to merge and sort two lists in ascending order.
  assert merge_sort([1, 3, 5, 6, 7], [4, 8, 9, 10]) == [1, 3, 4, 5, 6, 7, 8, 9, 10]
  assert merge_sort([10, 20, 30], [5, 15, 25, 35]) == [5, 10, 15, 20, 25, 30, 35]
  assert merge_sort([0, 2, 4], [1, 3, 5]) == [0, 1, 2, 3, 4, 5]
output: def merge_sort(list1, list2):
      merged_list = list1 + list2
      merged_list.sort()
      return merged_list