input: Write a function to generate a list of numbers starting from 0 to a given number with a step of 5.
  assert generate_list(30) == [0, 5, 10, 15, 20, 25]
  assert generate_list(20) == [0, 5, 10, 15]
  assert generate_list(10) == [0, 5]
output: def generate_list(n):
      return list(range(0, n, 5))