Make jupyter widgets render properly through sphinx

[mszell]

Currently, https://bikenetkit.github.io/GrowBikeNet/usage_02_network_growth/#Visualization does not render interactively.

These did not help unfortunately:

• https://stackoverflow.com/questions/65083665/how-do-i-get-juypter-widgets-to-render-properly-through-sphinx-and-nbconvert
• https://ipywidgets.readthedocs.io/en/stable/embedding.html#embedding-widgets-in-the-sphinx-html-documentation
• https://github.com/jupyter-widgets/ipywidgets/blob/80921ac9f9a18c43b02918ce3913818c188ae34c/docs/source/conf.py
• https://jupyter-sphinx.readthedocs.io/en/latest/index.html