input: Write a python function to find the index of an item in a list.
  assert find_index(5, [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]) == 4
  assert find_index(67, [10, 20, 45, 67, 84, 93]) == 3
  assert find_index(3, [5, 7, 9, 8, 6, 4, 3]) == 6
output: def find_index(item, lst):
      return lst.index(item)