[docs] updatation is needed

[Vaishali Ahire]

in documentation page of python 3.0 and current documentation  of
python tutorial there is missing break statement in  break and
continue statements example.
for n in range(2, 10):
...     for x in range(2, n):
...         if n % x == 0:
...             print(n, 'equals', x, '*', n//x)
...             break
...     else:
...         # loop fell through without finding a factor
...         print(n, 'is a prime number')

here extra break statement is required at the end of else loop.