Update README to indicate that VBO is needed to see Status

In the README file, under Setup, it states:

The signups tab for any signup-enabled node now contains an interface for managing the signup status of users and the node edit form for these nodes now contains fields for setting the enrollment limit for the various statuses.

But I am seeing no such functionality in Signup 6.x-1.0-dev (June 3, 2009). I also tried Signup Status with Signup 6.x-1.0-rc3?

According to this issue, we new Views and Views Bulk Operations. These instructions should really be included in the README.

http://drupal.org/node/406414

Thanks!