svelte: update tyings in test page

Author: flexponsive

packages/svelte/test-app/Pages/FormHelper/Data.svelte

@@ -1,7 +1,13 @@
 <script lang="ts">
   import { page, useForm } from '@inertiajs/svelte'
 
-  const form = useForm({
+  const form = useForm<{
+    name: string;
+    handle: string;
+    remember: boolean;
+    accept_tos?: boolean;
+    custom: Record<string, any>;
+  }>({
     name: 'foo',
     handle: 'example',
     remember: false,