docs: prefer shorter demo

src/slider/README.md

@@ -25,9 +25,7 @@ import { Toast } from 'vant';
 export default {
   setup() {
     const value = ref(50);
-    const onChange = (value) => {
-      Toast('Current value: ' + value);
-    };
+    const onChange = (value) => Toast('Current value: ' + value);
     return {
       value,
       onChange,
@@ -52,9 +50,7 @@ export default {
   setup() {
     // value must be an Array
     const value = ref([10, 50]);
-    const onChange = (value) => {
-      Toast('Current value: ' + value);
-    };
+    const onChange = (value) => Toast('Current value: ' + value);
     return {
       value,
       onChange,
@@ -132,9 +128,7 @@ export default {
   setup() {
     const value = ref(50);
     const value2 = ref([10, 50]);
-    const onChange = (value) => {
-      Toast('Current value: ' + value);
-    };
+    const onChange = (value) => Toast('Current value: ' + value);
     return {
       value,
       value2,

src/slider/README.zh-CN.md

@@ -29,9 +29,7 @@ import { Toast } from 'vant';
 export default {
   setup() {
     const value = ref(50);
-    const onChange = (value) => {
-      Toast('当前值：' + value);
-    };
+    const onChange = (value) => Toast('当前值：' + value);
     return {
       value,
       onChange,
@@ -56,9 +54,7 @@ export default {
   setup() {
     // 双滑块模式时，值必须是数组
     const value = ref([10, 50]);
-    const onChange = (value) => {
-      Toast('当前值：' + value);
-    };
+    const onChange = (value) => Toast('当前值：' + value);
     return {
       value,
       onChange,
@@ -138,9 +134,7 @@ export default {
   setup() {
     const value = ref(50);
     const value2 = ref([10, 50]);
-    const onChange = (value) => {
-      Toast('当前值：' + value);
-    };
+    const onChange = (value) => Toast('当前值：' + value);
     return {
       value,
       value2,

src/slider/demo/index.vue

@@ -95,9 +95,7 @@ export default {
       value9: [20, 60],
     });
 
-    const onChange = (value) => {
-      Toast(t('text') + value);
-    };
+    const onChange = (value) => Toast(t('text') + value);
 
     return {
       ...toRefs(state),