with-react-loadable 無法載入

嘗試利用 [with-react-loadable](https://github.com/alibaba/beidou/tree/master/examples/with-react-loadable) 的官方範例來實現 lazy loading

但在做完 `yarn build` 並且 `yarn start`時
點選 `http://127.0.0.1:6001/dynamic` 網址會一直卡在loading畫面

然後這是執行 `yarn build`之後的資料夾內容

貌似出錯原因是在dynamic這路徑底下找不到 `2.js`這個檔案
請問應該要如何做?

Reproduce the problem from examples/with-react-loadable by running yarn build and yarn start, then opening /dynamic at 127.0.0.1:6001. Inspect the build output and the dynamic route's loading request; done means the example loads instead of remaining on the loading screen and the expected chunk is available at the requested path.

Written by the indexing model from the issue text.