[SYNC] docs: add vite client script for backend integration (#9258)

[github-actions[bot]]

docs: add vite client script for backend integration (#9258) (aa0b921)

---

+++ b/docs/guide/backend-integration.md
@@ -33,6 +33,7 @@ If you need a custom integration, you can follow the steps in this guide to conf
```html
<!-- if development -->
+   <script type="module" src="http://localhost:5173/@vite/client"></script>
<script type="module" src="http://localhost:5173/main.js"></script>
```