launch on /lab by default

[raybellwaves]

Proposed change

When launching tljh for the first time in launches using /lab instead of /tree (classic) (

Alternative options

You can do it by hand after launch by running sudo tljh-config set user_environment.default_app jupyterlab

I also don't know how to pass this on at the build stage. e.g. to pass as an arg to

#!/bin/bash
curl -L https://tljh.jupyter.org/bootstrap.py \
  | sudo python3 - \
    --admin <user-name>

Who would use this feature?

Hopefully everyone as lab is more convient for dropping into a terminal for example to run sudo tljh-config commands

(Optional): Suggest a solution

Change https://github.com/jupyterhub/the-littlest-jupyterhub/blob/main/tljh/configurer.py#L52 to jupyterlab

May be something here as well https://jupyterlab.readthedocs.io/en/stable/user/jupyterhub.html#use-jupyterlab-by-default

[raybellwaves]

I learnt it's easy to do currently via a plugin e.g. https://github.com/yuvipanda/tljh-pangeo/blob/master/tljh_pangeo.py#L14-L22