Default Storageclass is needed as a prerequisite

[anencore94]

First of all, Thanks a lot for maintaining such a nice repo!!

I've been followed the guide with "Set up on JupyterHub", I found there needs one more prerequisite : "Setup Default Storageclass before helm install jupyterhub"

Otherwise, the deployment "hub" in jupyterflow namespace will at PENDING status forever, as well as the corresponding pvc "hub-db-dir"

I think it is not the jupyterflow's mistake, but the jupyterhub's mistake, There is an issue on here which says the prerequisite about default storageclass is needed on docs.

But, As a matter of jupyterflow uses the jupyterhub, I think the prerequisite of default storageclass should be commented in the "Setup guide" for jupyterflow.

[hongkunyoo]

Thank you for your suggestion and sorry for late reply.
I will add some prerequisite for Default Storage settings on documentations.