docs: add plugin setup guide

plugin/lib/commonlibf4/include/RE/C/CLASS_DATA.h

@@ -0,0 +1,13 @@
+#pragma once
+
+namespace RE
+{
+	class CLASS_DATA
+	{
+	public:
+		// members
+		std::int32_t serviceFlags;     // 0
+		float        bleedoutDefault;  // 4
+	};
+	static_assert(sizeof(CLASS_DATA) == 0x8);
+}