Add pre-borg step

[guyer]

As noted by @ianhbell via email: "It would be nice to have the chance to do some things pre-borging, for instance running doxygen and executing notebooks after borging is much more complicated with the fact that the doc folder has moved during borging and the hard-coded paths all need to be fixed up throughout my scripts and config files. It would be nice if this could run after the conda environment is loaded."

[ianhbell]

I added that in my fork, but I don't see a good way to do a PR with cherry picking into a feature branch because you need to test in main (or am I mistaken?)

[guyer]

In .github/workflows/NISTtheDocs2Death.yml, you can change usnistgov/NISTtheDocs2Death@main to my-fork/NISTtheDocs2Death@my-feature-branch. This won't be able to test the push to pages.nist.gov, but it should do the rest. For PRs on the usnistgov repo, usnistgov/NISTtheDocs2Death@my-feature-branch will exercise the full workflow.

[ianhbell]

Good I thought that might be the case but didn't get a chance to test yet