added Yoga and TinyXML2 libraries and created a testing layout.xml

engine/app.cpp

@@ -52,6 +52,12 @@ void App::init()
         "void main(){"
         "   frag = col;"
         "}";
+
+    tinyxml2::XMLDocument xml;
+    auto ret = xml.LoadFile("data\\layout.xml");
+    auto root = xml.RootElement();
+//    root->
+
     shader.create(shader_v, shader_f);
     shader_color.create(shader_color_v, shader_color_f);
     shader_uv.create(shader_v, shader_uv_f);