docs: Explain we prefer dir SWHIDs over rev/rel.
@rdicosmo I tried to write down the rationale you told me, as I couldn't find it written anywhere
What do you think?
Should I add also explain the scenario about asking people to run a program on their machine to recompute SWHIDs to recover lost artifacts, or would it be "too much" here?
Migrated from D7140 (view on Phabricator)