message: docs: extending release instructions
diff: the same time, also add a new empty "pending" section to the [release
  notes](docs/root/intro/version_history.rst) and to [DEPRECATED.md](DEPRECATED.md) for the
  following version. E.g., "1.7.0 (pending)".
  -* Run the deprecate_versions.py script to file tracking issues for code which
  - can be removed.
  +* Run the deprecate_versions.py script (e.g. `sh tools/deprecate_version/deprecate_version.sh 1.9.0 1.10.0`)
  + to file tracking issues for code which can be removed.
  ## When does a maintainer lose maintainer status
  