Write a function name getMonthsNeededToWait
that receives 2 numbers as parameters, representing the index of two months.
The function should return the number of months we have to wait, to get from the first month to the second one.
index1
=index2
=The month with index 1 is February and the month with index 3 is April. So, the number of months needed to wait is 2.
index1
=index2
=The month with index 11 is December and the month with index 0 is January. So, the number of months needed to wait is 1.