💚 Drop other library support and focus completely on Three.js + Add TS Support

[BraidenPsiuk]

I need to focus on my original intention - building a rendering-tools library for Three.js. Supporting other libraries would be nice and fits the name well, but at the same time I don't really know how to play nice with the whole ECMA Module system while also supporting like 5 libraries. So, I'm going to be rewriting fixar.js to only support Three.js so that I can start adding additional rendering tools. Since this will require major changes, this is a good time to add TS support/declarations.

[BraidenPsiuk]

Rewriting + adding TS support in branch three-focused.