docs: add plugin setup guide

plugin/lib/commonlibf4/include/RE/O/OBJ_TREE.h

@@ -0,0 +1,23 @@
+#pragma once
+
+namespace RE
+{
+	class OBJ_TREE
+	{
+	public:
+		// members
+		float trunkFlexibility;   // 00
+		float branchFlexibility;  // 04
+		float trunkAmplitude;     // 08
+		float frontAmplitude;     // 0C
+		float backAmplitude;      // 10
+		float sideAmplitude;      // 14
+		float frontFrequency;     // 18
+		float backFrequency;      // 1C
+		float sideFrequency;      // 20
+		float leafFlexibility;    // 24
+		float leafAmplitude;      // 28
+		float leafFrequency;      // 2C
+	};
+	static_assert(sizeof(OBJ_TREE) == 0x30);
+}