Hello. Thanks for this great library.

At the moment, it seems highlightJS is guessing the language based on the the file extension (I think Im reading that correctly here). That often results in incorrect matchings. If we know the language of the file that the diff is for, we'd like to specify it manually. Is there a way to do that? If not, could an option be added please? If you'd like us to add the option, could you point us in the direction you'd like us to do it please? And if its already an option and I've missed it, my apologies :)