fix examples for Yjs@13

examples/indexeddb/index.html

@@ -16,6 +16,9 @@
         width: 100%;
       }
     </style>
-    <script type="module" src="./index.js"></script>
+    <script src="../../y.js"></script>
+    <script src='../../../y-websockets-client/y-websockets-client.js'></script>
+    <script src='../../../y-indexeddb/y-indexeddb.js'></script>
+    <script src="./index.js"></script>
   </body>
 </html>