make enable step automagic

[AaronWatters]

Maarten Breddels @maartenbreddels 10:54
if you install a json file in a .d directory yes, but pip will not do that if you run pip install -e .
for ipyvolume this is the magic line

Aaron Watters @AaronWatters 10:55
I don't know what you mean "install a jspon file in a .d directory" -- I was doing "pip install jp_doodle" which had jp_proxy_widget as a dependency. I thought that was all I needed.
...and something got wedged somehow.

Maarten Breddels @maartenbreddels 10:57
I don't know that that proxy thing is.. but you need that magic line that ipyvolume has, it will put ipyvolume.json at {prefix}/etc/jupyter/nbconfig/notebook.d/