link to demo of embedding neuroglancer in a jupyter notebook

[d-v-b]

see https://github.com/holoviz-topics/neuro/blob/main/workflows/neuroglancer_notebook/neuroglancer-nb-workflow.ipynb. I think this workflow could be very attractive to a lot of people.

[d-v-b]

it might make sense to link to this demo from somewhere in the python docs

[jbms]

Yes, this seems like it would be of interest to a lot of people --- I'd be happy to take a PR that adds this to the "Related projects" section of the README, or potentially to the Python API docs somewhere though those docs are still kind of rough...