[enhancement] Add the black labextension

[rsignell-usgs]

Description

Would be cool to have the Black labextension available to Qhub users: https://coiled.io/blog/code-formatting-jupyter-notebooks-with-black/

[iameskild]

Hi @rsignell-usgs, could you try adding it to one of your conda environments (in the qhub-config.yaml) and redeploying? Although I haven't tried this with a qhub deployment yet, testing it in local jupyter lab session seemed to work :)

[rsignell-usgs]

@iameskild, I believe lab extensions need to get added into the environment that launches jupyterlab, not one of my defined conda environments. Is this right @tylerpotts, @aktech or @costrouc ?

[trallard]

@iameskild or @viniciusdc I think this should be easy to add to the new Docker images now that they are in nebari-dev can either of you take this on?

[iameskild]

@trallard @rsignell-usgs I've raised a PR to add jupyterlab_code_formatter :) https://github.com/nebari-dev/nebari-docker-images/pull/26