docs: add plugin setup guide

plugin/lib/commonlibf4/include/RE/S/SubtitleInfo.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include "RE/S/SUBTITLE_PRIORITY.h"
+
+namespace RE
+{
+	class SubtitleInfo
+	{
+	public:
+		// members
+		ObjectRefHandle               speaker;         // 00
+		BSFixedStringCS               subtitleText;    // 08
+		TESTopicInfo*                 topicInfo;       // 10
+		REX::TEnum<SUBTITLE_PRIORITY> priority;        // 18
+		float                         distFromPlayer;  // 1C
+	};
+	static_assert(sizeof(SubtitleInfo) == 0x20);
+}