There should be a a way to Un-emojify the DOM element

[gaurav414u]

Hi
So, while working with this library I figured out that there should be an API method to unemojify the DOM element which has the contents of ReactEmoji.emojify().
This will be very helpful in the cases where lets say we have a <div contentEditable='true'> and we are replacing every occurrence of ':annotation:' or 'emoticon (:) :D)' with the <img> tag while the user types in real-time. And when we want to compile this chat message and store it in db we can use the unemojify().
I have already added this support locally.
Let me if all of this makes sense and if I should make a pull request.
Thanks