Add Custom Search/URL Shortcuts to Firefox with Ready.to/search (ready.to)

I am moving to the new Firefox and needed a way to add a custom "search" with a letter shortcut for a URL shortener I use. (Ex: I type "b[space]phrase" in the URL bar and it opens "http://bit.ly/phrase".)

I could not figure this out natively in the settings and this page seemed to do the trick.

I am not the author/creator.