update examples with difficulty stars

examples/textures/textures_polygon.c

@@ -34,6 +34,8 @@ int main(void)
     const int screenHeight = 450;
     
     InitWindow(screenWidth, screenHeight, "raylib [textures] example - textured polygon");
+*
+*   Example complexity rating: [★☆☆☆] 1/4
 
     // Define texture coordinates to map our texture to poly
     Vector2 texcoords[MAX_POINTS] = {