cli: register the 'objstorage' cli subcommand
also add some docstrings to cli commands.
Related to swh-core#1671.
Migrated from D1475 (view on Phabricator)
Staging instance, all changes can be removed at any time
also add some docstrings to cli commands.
Related to swh-core#1671.
Migrated from D1475 (view on Phabricator)