Add an option / config for analytics tracking?

[TomDonoghue]

Would it be easy to add, in the notebook / config options, a way to add analytics / audience data, for example with Google Analytics? It's a while since I've set this up, but I think just adding a field in the config that people can fill in with google analytics ID might get most of the way there.

I've been meaning to add this to the books I have hosted, and just figured it could be something useful to add upstream - so thought I'd ask! I can look into this a bit more at some point - but just thought someone here might know quickly how to do this.

[choldgraf]

totally agree - I think it'd be great to make this possible. It'd need:

1. A little html in includes to include the GA snippet
2. A new configuration key like google_analytics: mytrackingcode.
3. Some short documentation explaining how to enable it, and linking to the GA code for generating your own analytics key

I'm happy to review a PR if you have a moment to try it out!

[joergbrech]

I have done something like this in my own jupyter book copy, I am happy to contribute.