docs: update demo for Pagination, close: #3944

components/pagination/demo/jump.md

@@ -16,7 +16,12 @@ Jump to a page directly.
 ````jsx
 import { Pagination } from 'antd';
 
+function onChange(pageNumber) {
+  console.log('Page: ', pageNumber);
+}
+
 ReactDOM.render(
-  <Pagination showQuickJumper defaultCurrent={2} total={500} />
-, mountNode);
+  <Pagination showQuickJumper defaultCurrent={2} total={500} onChange={onChange} />,
+  mountNode
+);
 ````