Add 'castling' sound to standard sound

[Teananazz]

I think it will be nice considering the fact that all popular chess sites also have sounds for castling.

The problem is that even if i want to change the sound of castling myself i can't.

In particular, the problem i am facing cannot be solved with just creating a script. The problem: I want to play a different sound when castling.

However, the code uses the exact same sound name for both moving and castling. But, i can't extract the moves made when playing against bots/humans (different from when analyzing of course) by just using the javascript presented through the document. (In simple words, i can't detect if someone castled or not)

The solution is probably just create a new sound name called 'castling' that will be played when "O-O" or "O-O-O" is played that can even have the same original sound as before, but it will help in the case of changing its sound. (Because in this case for example the name that will play is 'castling')

This is will also help others who are looking to customize the sound of their pieces so that they can have more fun.

There is also an alternative solution and that is allow people to read their game moves live (but i guess you don't want to do that for cheating reasons)

[Diceroller-is-Fire]

Lisp theme already has a castling sound

I can create it for other themes.