The rb-site documentation hasn't been touched in a while. Some of the

options we've had were missing, particulaly the ones most recently

added. This change adds those in, removes some old options, and polishes

soem instructions (particularly around rb-site manage).
Section reference names have been updated to be namespaced, to avoid

conflicts.

Built the docs. Checked for spelling and link errors.
Linked to some of the new options and the new section labels in the

upcoming release notes changes for 4.0 RC 1.