mostly done implementing callbacks for rgfw

todo.md

@@ -1,6 +1,5 @@
 # To-do list
 - Bind functions from RGFW (alternative back-end/window library) and have an option to use it
-  - Add callbacks so we can react to events. (Start by adding key callbacks.)
+  - Added most callbacks, including char callbacks, but I need to change the C side of the char callbacks so that symbols like [ become shifted properly.
 - Bind gamepad functions from GLFW
-- Modify deletion functions to use `PersistentVector.delete` 
 - Implement 'yj' motion and add tests for it