Is there an example of new test_uses/test_deps usage?

[david-bakin]

I couldn't find it in the docs in the develop branch (which is to say github search didn't find it) - I'd like to see how to use the new generic testing setup. (E.g., to substitute doctest for catch2.)

(Also, separately: why is the official doc site at "alpha3"? Are docs not updated yet for 4/5/6?)