Update index.html

index.html

@@ -18,6 +18,7 @@
         font-family: "Source Sans 3", sans-serif;
       }
     </style>
+    <script src="https://cdnjs.cloudflare.com/ajax/libs/iframe-resizer/4.3.1/iframeResizer.contentWindow.min.js"></script>
     <script src="https://cdn.tailwindcss.com"></script>
     <script type="module" src="./code.js"></script>
     <script type="module">