docs: add plugin setup guide

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

@@ -0,0 +1,18 @@
+#pragma once
+
+#include "RE/B/BSTSmartPointer.h"
+
+namespace RE
+{
+	class NavMesh;
+
+	class BGSNavmeshableObject
+	{
+	public:
+		static constexpr auto RTTI{ RTTI::BGSNavmeshableObject };
+
+		// members
+		BSTSmartPointer<NavMesh> embeddedNavmesh;  // 0
+	};
+	static_assert(sizeof(BGSNavmeshableObject) == 0x8);
+}