feat: publicize doc implemetation

one/docs/demo/calendar/default.vue

@@ -0,0 +1,39 @@
+<template>
+<article>
+  <veui-calendar v-model="date"/>
+  <p>Selected: {{ readableDate }}</p>
+</article>
+</template>
+
+<script>
+import { Calendar } from 'veui'
+
+export default {
+  components: {
+    'veui-calendar': Calendar
+  },
+  data () {
+    return {
+      date: new Date()
+    }
+  },
+  computed: {
+    readableDate () {
+      return this.date.toLocaleDateString(this.$i18n.locale, {
+        weekday: 'long',
+        year: 'numeric',
+        month: 'long',
+        day: 'numeric'
+      })
+    }
+  }
+}
+</script>
+
+<docs>
+支持 `v-model`，数据类型为原生 `Date` 类型。
+</docs>
+
+<docs locale="en-US">
+Supports `v-model` with value type being the native `Date`.
+</docs>