docs: add plugin setup guide

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

@@ -0,0 +1,12 @@
+#pragma once
+
+namespace RE
+{
+	class __declspec(novtable) BIPED_MODEL
+	{
+	public:
+		// members
+		std::uint32_t bipedObjectSlots;  // 0
+	};
+	static_assert(sizeof(BIPED_MODEL) == 0x4);
+}