UI for the notebook "old" client

[hadim]

As suggested here: https://discourse.jupyter.org/t/jupyter-archive-make-download-and-extract-archive-files/2363/13?u=hadim

[hadim]

I don't really have the time neither the need for this feature so I don't think I'll work on it in the near future. That being said I will be happy to review a PR.

[fcollonval]

As the classical notebook is retiring from active development, I let this issue open only if somebody is interested in implementing the feature.

Here are two repositories that could provide a code basis for this feature:

• https://github.com/data-8/nbzip
• https://github.com/ryanlovett/jupyter-tree-download

[fcollonval]

I'm closing this one as the classical notebook is retiring. For those interested by using this extension with a UI close to the classical notebook, I suggest using JupyterLab in simple mode.