Fix source distribution by including missing labextension and configs
Fix source distribution by including missing labextension and configs

Signed-off-by: martinRenou <a8278cece597ec79cc59974d3d55dbb79bb38416@gmail.com>

mwouts/jupytext,mwouts/jupytext,mwouts/jupytext,mwouts/jupytext,mwouts/jupytext,mwouts/jupytext,mwouts/jupytext,mwouts/jupytext,mwouts/jupytext,mwouts/jupytext