More Screen Swapping Stuff - Upstreamed project too

Okay so, there were a few of you who wanted to add more options to swap screens so I spent a few hours today doing just that. Luckily, @PalindromicBreadLoaf - the original dev who I forked this project from - added custom screens support. That helped a crazy lot.

L3 + Minus button should work for all screens now, as should be expected.

Have fun, I'm gonna go experiment on shader stuttering now.