[suggestion]Add pinchange interrupt and ISR() to the reference

It's probably me, but trying to find info how to use pinchange Interrupts seems impossible on this site

Reference (expected it here): no Libraries: no Playground: no (except for a link to a '3rd party' library) Search: seems to mostly search the forums

I eventually reverted to google which gave me (3rd hit) http://playground.arduino.cc/Main/PinChangeInterrupt

Although pinchangeInterrupt is not a function I suggest to add it to the reference section.

And while in the process of doing so, can ISR() also be added?