docs(select): update

docs/app/components/content/examples/select/SelectOpenExample.vue

@@ -0,0 +1,12 @@
+<script setup lang="ts">
+const open = ref(false)
+const items = ref(['Backlog', 'Todo', 'In Progress', 'Done'])
+
+defineShortcuts({
+  o: () => open.value = !open.value
+})
+</script>
+
+<template>
+  <USelect v-model:open="open" default-value="Backlog" :items="items" />
+</template>