[new feature] Tabs: add animated props to change tabs with animation (#2126)

docs/src/components/DemoList.vue

@@ -5,11 +5,24 @@
       <span>Vant</span>
     </h1>
     <div class="mobile-switch-lang">
-      <span :class="{ active: $vantLang === 'en-US' }" @click="switchLang('en-US')">EN</span>
-      <span :class="{ active: $vantLang === 'zh-CN' }" @click="switchLang('zh-CN')">中文</span>
+      <span
+        :class="{ active: $vantLang === 'en-US' }"
+        @click="switchLang('en-US')"
+      >
+        EN
+      </span>
+      <span
+        :class="{ active: $vantLang === 'zh-CN' }"
+        @click="switchLang('zh-CN')"
+      >
+        中文
+      </span>
     </div>
     <h2 class="zanui-desc">{{ description }}</h2>
-    <template v-for="item in navList" v-if="item.showInMobile">
+    <template
+      v-for="item in navList"
+      v-if="item.showInMobile"
+    >
       <mobile-nav
         v-for="(group, index) in item.groups"
         :group="group"
@@ -26,16 +39,16 @@ import MobileNav from './MobileNav';
 import { setLang } from '../utils/lang';
 
 export default {
+  components: {
+    MobileNav
+  },
+
   data() {
     return {
       docConfig
     };
   },
 
-  components: {
-    MobileNav
-  },
-
   computed: {
     navList() {
       return this.docConfig[this.$vantLang].nav || [];

docs/src/components/DemoPages.vue

@@ -8,8 +8,16 @@
         v-for="(demo, index) in demos"
       >
         <h4>{{ demo.title }}</h4>
-        <a :href="demo.source" target="_blank">{{ $t('source') }}</a>
-        <img :src="demo.preview" @click="onChangeDemo(demo, index)" >
+        <a
+          :href="demo.source"
+          target="_blank"
+        >
+          {{ $t('source') }}
+        </a>
+        <img
+          :src="demo.preview"
+          @click="onChangeDemo(demo, index)"
+        >
       </div>
     </div>
   </section>

docs/src/components/MobileNav.vue

@@ -1,6 +1,13 @@
 <template>
-  <van-collapse v-model="active" class="mobile-nav">
-    <van-collapse-item :title="group.groupName" :name="group.groupName" class="mobile-nav__item">
+  <van-collapse
+    v-model="active"
+    class="mobile-nav"
+  >
+    <van-collapse-item
+      class="mobile-nav__item"
+      :title="group.groupName"
+      :name="group.groupName"
+    >
       <van-cell
         v-if="!navItem.disabled"
         v-for="(navItem, index) in group.list"