update demo

components/table/__tests__/__snapshots__/demo.test.js.snap

@@ -3010,14 +3010,14 @@ exports[`renders ./components/table/demo/expand-children.md correctly 1`] = `
               class=""
             >
               <colgroup>
+                <col />
                 <col />
                 <col
-                  style="width:40%;min-width:40%"
+                  style="width:12%;min-width:12%"
                 />
                 <col
                   style="width:30%;min-width:30%"
                 />
-                <col />
               </colgroup>
               <thead
                 class="ant-table-thead"

components/table/demo/expand-children.md

@@ -24,15 +24,15 @@ const columns = [{
   title: 'Name',
   dataIndex: 'name',
   key: 'name',
-  width: '40%',
 }, {
   title: 'Age',
   dataIndex: 'age',
   key: 'age',
-  width: '30%',
+  width: '12%',
 }, {
   title: 'Address',
   dataIndex: 'address',
+  width: '30%',
   key: 'address',
 }];