docs(NavBar): use setup

src/contact-card/README.md

@@ -22,10 +22,13 @@ app.use(ContactCard);
 import { Toast } from 'vant';
 
 export default {
-  methods: {
-    onAdd() {
+  setup() {
+    const onAdd = () => {
       Toast('add');
-    },
+    };
+    return {
+      onAdd,
+    };
   },
 };
 ```

src/contact-card/README.zh-CN.md

@@ -26,10 +26,13 @@ app.use(ContactCard);
 import { Toast } from 'vant';
 
 export default {
-  methods: {
-    onAdd() {
+  setup() {
+    const onAdd = () => {
       Toast('新增');
-    },
+    };
+    return {
+      onAdd,
+    };
   },
 };
 ```

src/nav-bar/README.md

@@ -29,13 +29,17 @@ app.use(NavBar);
 import { Toast } from 'vant';
 
 export default {
-  methods: {
-    onClickLeft() {
+  setup() {
+    const onClickLeft = () => {
       Toast('Back');
-    },
-    onClickRight() {
+    };
+    const onClickRight = () => {
       Toast('Button');
-    },
+    };
+    return {
+      onClickLeft,
+      onClickRight,
+    };
   },
 };
 ```

src/nav-bar/README.zh-CN.md

@@ -29,13 +29,17 @@ app.use(NavBar);
 import { Toast } from 'vant';
 
 export default {
-  methods: {
-    onClickLeft() {
+  setup() {
+    const onClickLeft = () => {
       Toast('返回');
-    },
-    onClickRight() {
+    };
+    const onClickRight = () => {
       Toast('按钮');
-    },
+    };
+    return {
+      onClickLeft,
+      onClickRight,
+    };
   },
 };
 ```

src/nav-bar/demo/index.vue

@@ -19,24 +19,36 @@
   </demo-block>
 </template>
 
-<script>
-export default {
-  i18n: {
+<script lang="ts">
+import { useTranslate } from '@demo/use-translate';
+import Toast from '../../toast';
+
+const i18n = {
   'zh-CN': {
     useSlot: '使用插槽',
   },
   'en-US': {
     useSlot: 'Use Slot',
   },
-  },
+};
 
-  methods: {
-    onClickLeft() {
-      this.$toast(this.t('back'));
-    },
-    onClickRight() {
-      this.$toast(this.t('button'));
-    },
+export default {
+  setup() {
+    const t = useTranslate(i18n);
+
+    const onClickLeft = () => {
+      Toast(t('back'));
+    };
+
+    const onClickRight = () => {
+      Toast(t('button'));
+    };
+
+    return {
+      t,
+      onClickLeft,
+      onClickRight,
+    };
   },
 };
 </script>