docs(form): improve types

docs/app/components/content/examples/form/FormExampleNested.vue

@@ -18,7 +18,7 @@ type NestedSchema = z.output<typeof nestedSchema>
 const state = reactive<Partial<Schema & NestedSchema>>({ })
 
 const toast = useToast()
-async function onSubmit(event: FormSubmitEvent<any>) {
+async function onSubmit(event: FormSubmitEvent<Schema>) {
   toast.add({ title: 'Success', description: 'The form has been submitted.', color: 'success' })
   console.log(event.data)
 }