Publish checkbox frozen

I've tested and the module works as expected.
@David Fiaty, please go to the admin/config/workflow/publishcontent and enable 'Publish and unpublish via checkbox' if you want to have this possibility.

But it could be great to have this option enabled by default, so I'm making a merge request for maintainers to decide.

The suggestion works indeed. However I believe a freshly installed module shouldn't change any core Drupal config parameter without user action. Great work and thank you very much for the quick reply.