docs: add plugin setup guide

plugin/lib/commonlibf4/include/RE/I/IDLE_REPLAY_DELAY.h

@@ -0,0 +1,15 @@
+#pragma once
+
+namespace RE
+{
+	class TESIdleForm;
+
+	class IDLE_REPLAY_DELAY
+	{
+	public:
+		// memberse
+		const TESIdleForm* idleForm;  // 00
+		float              delay;     // 08
+	};
+	static_assert(sizeof(IDLE_REPLAY_DELAY) == 0x10);
+}