input: Write a python function to generate a multiplication table up to ten for a given number.
  assert generate_multiplication_table(2) == "2 * 1 = 2\n2 * 2 = 4\n2 * 3 = 6\n2 * 4 = 8\n2 * 5 = 10\n2 * 6 = 12\n2 * 7 = 14\n2 * 8 = 16\n2 * 9 = 18\n2 * 10 = 20\n"
  assert generate_multiplication_table(5) == "5 * 1 = 5\n5 * 2 = 10\n5 * 3 = 15\n5 * 4 = 20\n5 * 5 = 25\n5 * 6 = 30\n5 * 7 = 35\n5 * 8 = 40\n5 * 9 = 45\n5 * 10 = 50\n"
  assert generate_multiplication_table(9) == "9 * 1 = 9\n9 * 2 = 18\n9 * 3 = 27\n9 * 4 = 36\n9 * 5 = 45\n9 * 6 = 54\n9 * 7 = 63\n9 * 8 = 72\n9 * 9 = 81\n9 * 10 = 90\n"
output: def generate_multiplication_table(n):
      return '\n'.join(f"{n} * {i} = {n * i}" for i in range(1, 11)) + '\n'