without CodeTour needing to do anything about it, you can just use git and name CodeTour based on git tag, hash or something.
Edit: It actually can reference a git ref, WOW: https://github.com/microsoft/codetour#versioning-tours
Edit: It actually can reference a git ref, WOW: https://github.com/microsoft/codetour#versioning-tours
In general, I've seen a pretty great reaction from folks about the concept of CodeTour, and so I'm very focused on making them maintainable, since I believe that's the "big rock" needed to make them a worthy investment for more teams.
I personally envision using it for onboarding new developers to a code base, in which case I think being on an older ref should be fine, since I'm just trying to show the general structure of a project.
I could also see using it in a code review context, in which case pointing it at the branch would also be fine.
Also, if you look at the schema it generates for a tour, it would be pretty easy to go through and update the line numbers directly in the JSON.