input: Write a python function to generate a list of squares from a given list of numbers.
  assert generate_squares([1, 2, 3, 4, 5]) == [1, 4, 9, 16, 25]
  assert generate_squares([0, -1, -2, -3, -4]) == [0, 1, 4, 9, 16]
  assert generate_squares([10, 20, 30]) == [100, 400, 900]
output: def generate_squares(numbers):
      return [x**2 for x in numbers]