Investigate runnable example documentation in ReadTheDocs

[drewoldag]

@mjuric brought this up during our sync meeting, and no one had a chance to investigate, so we're documenting it here so it won't fall off the backlog.

"Determine if there’s a way to make documentation examples runnable. Some utility with ReadTheDocs that allows marking a block of code as runnable, so that it exists as a unit test. In particular, the “getting started” CLI stuff."

[mschwamb]

I think this is what we need to be using https://www.sphinx-doc.org/en/master/usage/extensions/doctest.html