Ongoing updates and improvements

[wendellpiez]

Committer Notes

A few ongoing improvements and touchups.

The PR is partly for the purposes of testing PR infrastructure.

All Submissions:

• [x] Follow Contributing guidelines
• [x] Make no changes addressing issues being addressed in other open Pull Requests
• [ ] Have been squashed to keep only relevant interim commits, if any [instructions]
• [ ] Have been tested manually
• [ ] Pass all CI/CD checks

Changes to Core Features:

• [x] The Issue history, discussions and new documentation provide context for new features -- everything is reasonably self-explanatory
• [x] New tests are included
• [x] New examples are included
• [x] Everything in readme and TESTING documents has been updated

[aj-stein-nist]

Hi @wendellpiez, are you going to merge this? It determines where my CI/CD PR ends up. I thought it would be merged by now, and made a separate branch. I guess I will PR to the wendellpiez/oscal-xproc3 fork then, FYI.

[wendellpiez]

Thanks for all the help @iMichaela @galtm and @aj-stein-nist !