input: Write a function to generate a multiplication table with numbers in a range given start and end parameters. Return the multiplication table as a string.
  def multiplication_table(start, end):
  	result = ""
  	for x in range(start, end + 1):
  		for y in range(start, end + 1):
  			result += str(x * y) + "  "
  		result += "\n"
  	return result
  
  assert multiplication_table(5, 10) == "25  30  35  40  45  50  \n30  36  42  48  54  60  \n35  42  49  56  63  70  \n40  48  56  64  72  80  \n45  54  63  72  81  90  \n50  60  70  80  90  100  \n"
  assert multiplication_table(3, 6) == "9  12  15  18  \n12  16  20  24  \n15  20  25  30  \n18  24  30  36  \n"
  assert multiplication_table(1, 1) == "1  \n"
  assert multiplication_table(2, 2) == "4  \n"
  assert multiplication_table(0, 0) == "0  \n"
output: def multiplication_table(start, end):
  	result = ""
  	for x in range(start, end + 1):
  		for y in range(start, end + 1):
  			result += str(x * y) + "  "
  		result += "\n"
  	return result