Added TypeScript implementation of the library

[joecoolish]

First stab at a TypeScript implementation of the library. The comments might not have fully gotten ported over, but I'm pretty sure the logic is all there!

[benmarch]

😲 Wow!! This is awesome! Let's get it all set up with separate modules and hooked into the build script. I do want to tackle the positioning issues before porting everything, but after that I will start integrating this. Thanks!

[joecoolish]

Which position issues are you still seeing? I have notice 2. The one I commented on, which is fixed by adding left: 0; to the left blackout box, and an overlapping border caused by rounding. The fix I found for that was to round all of the positions.

I can work on separating the different classes into individual files. I'm also working on making the backdrop fade in/out.

I'm using this in one of my projects ATM, so I'm invested in making it better

[joecoolish]

Ok, I fixed a couple of bugs in this PR. I'm now running the TS in my project and it is fully functional. I'll start working on the backdrop, making it more polished.