Add complete multiplayer system with real-time gameplay, challenge system, and 50x50 board option

node_modules/gopd/index.js

@@ -0,0 +1,15 @@
+'use strict';
+
+/** @type {import('.')} */
+var $gOPD = require('./gOPD');
+
+if ($gOPD) {
+	try {
+		$gOPD([], 'length');
+	} catch (e) {
+		// IE 8 has a broken gOPD
+		$gOPD = null;
+	}
+}
+
+module.exports = $gOPD;