request to add jupyterlab documentation

[Tilana]

This code is really good resource to get started with binder and RISE. Unfortunately, with JupyterLab being the default for binder the documentation is a bit misleading. For example the results from clicking on the binder link in the readme and building this repo on mybinder.org are not equal. For the latter, the presentation is neither started automatically nor is the Enter / Exit RISE Slideshow button displayed.

I solved this by the url https://hub-binder.mybinder.ovh/user/binder-examples-jupyter-rise-kn2gvl6r/doc/tree/index.ipynb with https://hub-binder.mybinder.ovh/user/binder-examples-jupyter-rise-kn2gvl6r/notebooks/index.ipynb

I'm sure there are smarter options :) I hope adding this information to the README.md could save some time for other people.