docs: improve form docs (#761)

Co-authored-by: Haytham A. Salama <haythamasalama@gmail.com>

docs/components/content/examples/FormExampleYup.vue

@@ -1,5 +1,4 @@
 <script setup lang="ts">
-import { ref } from 'vue'
 import { object, string, InferType } from 'yup'
 import type { FormSubmitEvent } from '@nuxt/ui/dist/runtime/types'
 
@@ -12,7 +11,7 @@ const schema = object({
 
 type Schema = InferType<typeof schema>
 
-const state = ref({
+const state = reactive({
   email: undefined,
   password: undefined
 })