feat(Cascader): basic dom struct

src/cascader/demo/index.vue

@@ -1,6 +1,6 @@
 <template>
   <demo-section>
-    <demo-block :title="t('basicUsage')">
+    <demo-block card :title="t('basicUsage')">
       <van-field
         is-link
         readonly
@@ -8,17 +8,22 @@
         :placeholder="t('selectArea')"
         @click="showBase = true"
       />
-      <van-cascader :show.sync="showBase" :title="t('selectArea')" />
+      <van-popup v-model="showBase" round position="bottom">
+        <van-cascader :title="t('selectArea')" :options="t('options')" />
+      </van-popup>
     </demo-block>
   </demo-section>
 </template>
 
 <script>
+import zhCNOptions from './area';
+
 export default {
   i18n: {
     'zh-CN': {
       area: '地区',
       selectArea: '请选择地区',
+      options: zhCNOptions,
     },
     'en-US': {
       area: 'Area',