Split the game core and ui code into their respective modules

Game state struct ends the variable mess in main.c

ui.h

@@ -0,0 +1,9 @@
+#pragma once
+#include <raylib.h>
+#include "game.h"
+
+#define TILE_SIZE 100
+#define TILE_SPACING 10
+#define BOARD_MARGIN 50
+
+void handle_mouse_input(GameState_t *game_state);