No need to take any action on this, but I thought it might be of interest.
I forked this library and I wanted to be able to use webpack and yarn. I have managed to get everything installing and up and running (including a very fast (a second or two) hot-reload).
If you want to see the changes I made see the following:
https://github.com/pymedphys/pymedphys/tree/5168a77b3068ea4b247e11c62b60d92229271cb7/packages/pymedphys_sphinxtheme