Added new function Simple.compare()

This new function is used for evaluating a sequence
of values. Each of the Simple.is functions were
using a private version of this function, so it
made sense to make it publically facing instead.
Readme updated

Shortened the description of LudusJS.
All references to "Simple" have been replaced
with "Ludus" to accomidate the renaming of the
repo.
All missing functions have been added to the
documentation listing.
Added "How to Use" section.