SiNKR 2 Mult-Step Undo

Hey Everyone,

I pushed a big update to SiNKR 2 today from changes backported from SiNKR 3! Mult-step undo is the biggest one. Here is the full list:

•  Multi-step undo including undo past level failure and level reset
•  Keyboard and controller mapping, including new bindings for next level `N` and previous level `B`
•  Level selector zoom in/out controls
•  Engine updates bring UI refinements, color grading, and dithering

I'm currently working to push these same changes to the original SiNKR.