make window test

much of this is based on cross-referencing from
the sdl3 snake demo:
https://examples.libsdl.org/SDL3/demo/01-snake/

i need to work out an elegant system for logging.
probably involving macro wonk.

dat.h

@@ -0,0 +1,5 @@
+typedef struct State State;
+struct State {
+	SDL_Window *win;
+	SDL_Renderer *ren;
+};