feat: add colors to vao and shaders

shaders/simple.vert

@@ -1,7 +1,10 @@
 #version 460 core
 
 in layout(location=0) vec3 position;
+in layout(location=1) vec4 aColor;
+out vec4 vColor;
 
 void main() {
     gl_Position = vec4(position, 1.0f);
+    vColor = aColor;
 }