docs: add plugin setup guide

plugin/lib/commonlibf4/include/RE/B/BSFurnitureMarker.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include "RE/N/NiPoint3.h"
+
+namespace RE
+{
+	class BSFurnitureMarker
+	{
+	public:
+		// members
+		NiPoint3      position;              // 00
+		BGSKeyword*   actorMustHaveKeyword;  // 10
+		float         heading;               // 18
+		std::uint32_t allowedAnimations;     // 1C
+	};
+	static_assert(sizeof(BSFurnitureMarker) == 0x20);
+}