Document local-directory volumes in the Jobs configuration guide (#2620)
huggingface_hub v1.22.0 added local directories as -v sources (synced to the
private jobs-artifacts bucket). Extends the Volumes section: table row, a
short Local directories subsection with read-only-by-default + :rw, output
pull-back, scheduled-jobs behavior, and a link to the sync_job_volume guide.
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>