added section for file loading + memory cleanup

Make sure to clean up any memory allocated to the sim in terms of
disassembly instructions etc

src/simulator/gui.odin

@@ -115,6 +115,9 @@ run_gui :: proc(sim: ^Simulator) {
 	rl.UnloadSound(beep)
 	rl.CloseAudioDevice()
 	rl.CloseWindow()
+
+	// Free any allocated memory for the simulator
+	delete(sim.disasm)
 }
 
 // @TODO: If this grows lets move it into its own file
@@ -128,6 +131,7 @@ calc_layout :: proc(screen_width: f32, screen_height: f32) -> Layout {
 	sidebar_width	   := screen_width * SIDEBAR_PERCENT
 	display_width	   := screen_width - (sidebar_width * 2) - sidebar_width
 	display_height	   := visible_height * DISPLAY_V_RATIO
+	keypad_height	   := (y_pos + visible_height - visible_height / 2)
 
 	x_center		   := sidebar_width
 	y_center		   := screen_width - sidebar_width * 2
@@ -144,11 +148,11 @@ calc_layout :: proc(screen_width: f32, screen_height: f32) -> Layout {
 			x = 0,
 			y = y_pos,
 			width = sidebar_width,
-			height = visible_height / 3
+			height = keypad_height - y_pos
 		},
 		keypad = rl.Rectangle{
 			x = 0,
-			y = (y_pos + visible_height - visible_height / 2),
+			y = keypad_height,
 			width = sidebar_width,
 			height = visible_height / 2
 		},