Refactor `rhoso_adoc_docs_to_test.py` in case this repository has a longer future ahead

[lpiwowar]

This file is now well past the point of being a maintainable script. It may very well work. But I can't see how anyone could make sense of it in two months, or half a year. If possible, it should be cut into simpler parts, or slimmed down somehow.

Originally posted by @jpodivin in #71