docs: add plugin setup guide

plugin/lib/commonlibf4/include/RE/U/UsesBSGFXFunctionHandler.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include "RE/B/BSGFxFunctionBase.h"
+#include "RE/B/BSTArray.h"
+
+namespace RE
+{
+	class UsesBSGFXFunctionHandler
+	{
+	public:
+		static constexpr auto RTTI{ RTTI::UsesBSGFXFunctionHandler };
+
+		// members
+		BSTArray<std::unique_ptr<BSGFxFunctionBase>> functions;  // 00
+	};
+	static_assert(sizeof(UsesBSGFXFunctionHandler) == 0x18);
+}