Outdated stable branch and malfunctional mybinder.org badge

还没有人认领这个 Issue。

Visiting this repos mybinder example, both using the old stable branch as in the README, or the current master branch, gives us:



This is because mybinder.org won't automatically realize it should install the jupyterlab extension. We would need an apt.txt file in the repo for that to happen where we write:

```
jupyter labextension install @jupyter-widgets/jupyterlab-manager
jupyter labextension install jupyter-matplotlib
```

Also, update the readme to use the master branch may be simpler than remembering to update the stable branch?

首先检查 README 中 MyBinder 徽章的 URL，以及是否存在 apt.txt 文件，然后在文档所述的分支上启动所引用的 MyBinder 示例。完成的标准是：徽章能够打开一个配备所需 JupyterLab 扩展的可用环境，并且 README 指向预期的分支。

由索引模型根据 Issue 内容生成。