Start jupyverse automatically on Binder

[jtpio]

Problem

At the moment we have to start jupyverse by running a couple of notebook cells on Binder:

Maybe should add the jupyter-server-proxy config to automatically run the command on startup. And use the ?urlpath= in the Binder URL to redirect to the jupyverse-served frontend on startup.

Proposed Solution

We add a jupyter_notebook_config.py that sets up the jupyter-server-proxy config.

Additional context