Unique, interesting idea
Not very useful
UPDATE: It seems like that link is so long it's being cut off, so here's a shortened one: https://bit.ly/2NC8nzK
It's really neat that this whole thing can fit in a URL, but what advantage would this have over other products? For example, put the same example on CodePen and you have a much better user experience (clean code, less work), while both enjoy the benefits of free hosting on someone else's server.: https://codepen.io/cbejensen/pen/ppQgRb
UPDATE: After writing the above paragraph, I realized you can paste CodePen links into the itty bitty editor.I am not sure this increases the usefulness of this app, but it is interesting.
Maybe a coding reference just isn't a good way to use this product. But that's the big question - what is a good use case for this product? What problem does this solve that other apps cannot solve better?
In summary, it's fun to consider the idea, but not ultimately all that useful.