input: Write a python function to find the minimum value in a list.
  assert min_list([4, 2, 8, 6, 1]) == 1
  assert min_list([10, 20, 30, 5, 50]) == 5
  assert min_list([100, 200, 300, 10, 500]) == 10
output: def min_list(lst):
      return min(lst)