Install persistent jupyter extensions?

[jbusecke]

On my local machine I have a few extensions that I have come to depend on quite a bit. In particular, I find jupyterlab_code_formatter extremely useful.

Is there a way to install/enable extensions similar to pip packages? Or would it only be feasible to install extensions on the main docker image (related to #142)?

In the latter case I am not sure if this one is of broad enough use? Id argue yes, but there might be other opinions out there.