docs: add plugin setup guide

plugin/lib/commonlibf4/include/Scaleform/R/Render_Rect.h

@@ -0,0 +1,22 @@
+#pragma once
+
+namespace Scaleform::Render
+{
+	template <class T>
+	class RectData
+	{
+	public:
+		// members
+		T x1;  // 00
+		T y1;  // ??
+		T x2;  // ??
+		T y2;  // ??
+	};
+
+	template <class T>
+	class Rect :
+		public RectData<T>  // 00
+	{
+	public:
+	};
+}