docs(NavBar): use setup

src/nav-bar/demo/index.vue

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