docs: add plugin setup guide

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

@@ -0,0 +1,18 @@
+#pragma once
+
+#include "RE/B/BSIntrusiveRefCounted.h"
+#include "RE/B/BoneData.h"
+#include "RE/N/NiMatrix3.h"
+
+namespace RE
+{
+	class BaseTreeData :
+		public BSIntrusiveRefCounted  // 00
+	{
+	public:
+		// members
+		BSTArray<BoneData>  branchBoneData;            // 08
+		BSTArray<NiMatrix3> parentWorldBoneRotations;  // 20
+	};
+	static_assert(sizeof(BaseTreeData) == 0x38);
+}