Allow for exercise-specific (generic) content about deprecated-mentors

[iHiD]

Thanks for the idea! :)

I think that a key point of Exercism is that different languages have different idioms. Therefore I think there is probably a lot less overlap in exercises than one might expect. There will of course be similar groupings of languages that have overlap, but I think few general rules.

Specifically Exercism is about teaching what makes that language different, rather than teaching you how to code and the language itself being coincidental. For example, there are very few languages that care about algorithmic complexity as an first-level citizen. For example, I want the Ruby exercises to teach the difference between ** and pow and abs2, not how to write good algorithms that happen to be in Ruby.

I may, of course, be wrong here, but I would like to see some solid examples of where this would be useful before thinking more about it. :)