Clarify what workbench module itself is required for

Just found this on the documentation page, but it should probably be on the main project page:

The Workbench module itself provides a nice landing page to see your user profile and your content. It also provides easy access to create new content (with the ability to extend with additional Workbench modules.

On the project page of https://www.drupal.org/project/workbench_moderation

...we have a similar need for (this) clarification:

"Workbench Moderation may be run as a stand-alone module with no dependencies; however, certain features are available only when the Workbench module is also enabled."