docs(tabs): update examples

docs/app/components/content/examples/tabs/TabsSelectedExample.vue

@@ -0,0 +1,23 @@
+<script setup lang="ts">
+const items = [
+  {
+    label: 'Account'
+  },
+  {
+    label: 'Password'
+  }
+]
+
+const selected = ref('1')
+
+// Note: This is for demonstration purposes only.
+onMounted(() => {
+  setInterval(() => {
+    selected.value = selected.value === '0' ? '1' : '0'
+  }, 1000)
+})
+</script>
+
+<template>
+  <UTabs v-model="selected" :content="false" :items="items" />
+</template>