[C 18:49:50.816 NotebookApp] Bad config encountered during initialization:
[C 18:49:50.816 NotebookApp] The 'contents_manager_class' trait of a NotebookApp instance must be a subclass of 'notebook.services.contents.manager.ContentsManager', but a value of class 'traitlets.traitlets.MetaHasTraits' (i.e. <class 'notedown.contentsmanager.NotedownContentsManager'>) was specified.
http://zh.gluon.ai/chapter_crashcourse/install.html
里面可以查找下面這段話：
使用notedown插件來讀寫github源文件
注意：這個只推薦給如果想上github提交改動的小伙伴。 我們源代碼是用markdown格式來存儲，而不是jupyter默認的ipynb格式。我們可以用notedown插件來讀寫markdown格式。下面命令下載源代碼並且安裝環境：
git clone https://github.com/mli/gluon-tutorials-zh
cd gluon-tutorials-zh
conda env create -f environment.yml
source activate gluon # Windows下不需要 source
然后安裝notedown，運行Jupyter並加載notedown插件：
pip install https://github.com/mli/notedown/tarball/master
jupyter notebook --NotebookApp.contents_manager_class=‘notedown.NotedownContentsManager’
【可選項】默認開啟notedown插件
首先生成jupyter配置文件（如果已經生成過可以跳過）
jupyter notebook --generate-config
將下面這一行加入到生成的配置文件的末尾（Linux/macOS一般在~/.jupyter/jupyter_notebook_config.py)
c.NotebookApp.contents_manager_class = ‘notedown.NotedownContentsManager’
之后就只需要運行jupyter notebook即可。
https://discuss.gluon.ai/t/topic/757