'AppBar with a custom bottom widget' page issue

[evan361425]

Page URL: https://flutter-es.io/docs/catalog/samples/app-bar-bottom.html
Page source: https://github.com/flutter-es/website/tree/dash/src_es/docs/catalog/samples/app-bar-bottom.md

Image broken, the link: https://storage.googleapis.com/flutter-catalog/cb4a54db8fb3726bf4293b9cc5cb12ce16883803/app_bar_bottom_small.png