Update jqueryui.d.ts

jqueryui/jqueryui.d.ts

@@ -976,6 +976,7 @@ interface JQuery {
     sortable(methodName: 'disable'): void;
     sortable(methodName: 'enable'): void;
     sortable(methodName: 'widget'): JQuery;
+    sortable(methodName: 'toArray'): string[];
     sortable(methodName: string): JQuery;
     sortable(options: JQueryUI.SortableOptions): JQuery;
     sortable(optionLiteral: string, optionName: string): any;