docs: add plugin setup guide

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

@@ -0,0 +1,23 @@
+#pragma once
+
+namespace Scaleform::Render
+{
+	template <class C, std::int32_t N>
+	class PagedItemBuffer
+	{
+	public:
+		class Page
+		{
+		public:
+			// members
+			Page*        next;      // 00
+			std::int32_t count;     // 08
+			C            items[N];  // ??
+		};
+
+		// members
+		Page* pages;  // 00
+		Page* last;   // 08
+	};
+	static_assert(sizeof(PagedItemBuffer<void*, 0>) == 0x10);
+}