Added splitter founction to convertElement

If splitter is provided, it outputs a prefix for the new innerText of an
element (such as "2 cups").
Implemented default splitter function

It takes in the string and a units string[] of words like "cup" and
"cups." It looks for those units and returns everything up to that word,
then looks for numbers, then just returns nothing.
Got FoodNetwork support for string splitting

FoodNetwork.com is a perfect example of a really shitty site that takes
forever to load.
Food.com support