docs: add plugin setup guide

plugin/lib/commonlibf4/include/RE/W/WORLD_MAP_DATA.h

@@ -0,0 +1,17 @@
+#pragma once
+
+namespace RE
+{
+	class WORLD_MAP_DATA
+	{
+	public:
+		// members
+		std::uint32_t usableWidth;   // 00
+		std::uint32_t usableHeight;  // 04
+		std::int16_t  nwCellX;       // 08
+		std::int16_t  nwCellY;       // 0A
+		std::int16_t  seCellX;       // 0C
+		std::int16_t  seCellY;       // 0E
+	};
+	static_assert(sizeof(WORLD_MAP_DATA) == 0x10);
+}