Exporting JupyterGIS session to .qgz does not preserve local file paths

[martinRenou]

          Does this actually work when the local file is not in the same folder as the JGIS file?

e.g. if the JGIS file points to the geojson file in another folder ../path/to/my.geo.json?

I understand from the code only my.geo.json will be kept

Originally posted by @martinRenou in #390 (comment)