feat: publicize doc implemetation

one/docs/demo/dialog/draggable.vue

@@ -0,0 +1,38 @@
+<template>
+<article>
+  <veui-button @click="draggableOpen = true">
+    Draggable
+  </veui-button>
+  <veui-dialog
+    :open.sync="draggableOpen"
+    title="Draggable Dialog"
+    draggable
+    @ok="draggableOpen = false"
+    @cancel="draggableOpen = false"
+  >
+    This dialog is draggable.
+  </veui-dialog>
+</article>
+</template>
+
+<script>
+import { Dialog, Button } from 'veui'
+
+export default {
+  components: {
+    'veui-dialog': Dialog,
+    'veui-button': Button
+  },
+  data () {
+    return {
+      draggableOpen: false
+    }
+  }
+}
+</script>
+
+<style lang="less" scoped docs>
+.veui-button {
+  margin-right: 20px;
+}
+</style>