Clarify or expand use case

It isn't totally clear to me if the dashboard is intended to monitor status of packages from the developer/contributor or user POV. Maybe you could make that more clear in the `README`?

The reason I bring it up: I just updated R and, therefore, all of my packages. This is easy for things I'm using from CRAN but much more manual for packages I install from GitHub. Could the dashboard somehow assist a user with determining the status of packages that one has installed from GitHub?

`update.packages()` and `old.packages()` are very informative re: packages on CRAN. But if you're tracking the GitHub versions of certain packages, it would be nice to know how far behind you are, whether the current status is "build passing", etc.

Start with the README and the dashboard’s current package-status behavior. Clarify whether the project targets contributors or package users, then assess the requested status information for packages installed from GitHub. Done means the intended use case is explicit and the scope of any supported GitHub package tracking is defined.

Written by the indexing model from the issue text.