Right now, our doc generation scripts notice if you make changes and
don't regen docs, don't include new docs, etc. But they miss it if your
changes should have REMOVED a doc. Both kubectl-apiversion and
kubectl-clusterinfo should have been removed, but weren't.
This patch starts tracking all generated doc files and will cause
problems if files should be removed and aren't.
This does away with the giant dump from cobra for kubectl and instead
generates md files which contain similar information, but one per verb.
This might work well as part of the cobra project, instead of doing it
in kube, but this gets us nice, linked, documentation right now. If
people like it, I will try to get something similar into cobra.