Serve an "info" page for a Built Binder

There have been a few moments where people want access to meta information about a Binder from within a live session. A few that come to mind:

1. What is the “sharable link” for a Binder repository?
2. What is the github repo link that a Binder repository was built from?
3. Where are the logs for the build process?
4. Something @bitnik implemented - what is the token for my private binder repo so that I can share it with others

What if we created an info/ page that was generated for each Binder repository. This could live at https://hub.mybinder.org/user/<pod-name>/info and would be a simple page with auto-generated HTML. Perhaps this could be a way to provide this information for people, without making a custom UI edit to the notebook/lab/rstudio/etc UI. What do folks think?

[choldgraf]

@willingc yep, I believe so. I think the GESIM folks are already using this. Basically, they have a button at the top of their page that, when clicked, gives you the URL to your live session that you can share with others. Presumably for collaboration and sharing live sessions. I think that deployment has different security concerns (e.g. it’s authenticated, I believe), but I thought it was a very interesting idea

[choldgraf]

In this case I meant “sharing the notebook token for your session so that other people can connect to it”. Not “using private github repos”. I think @willingc and you make a good point re: avoiding sharing personal session tokens, so I’m happy not to have that in there.