Updating dox for mod_rest. Ideas expressed / clarified: 1) Making clear that mod_rest isn't to be installed under VirtualHosts AND as a component. 2) Understanding some of the implications of this choice: A) Changes to user authentication B) How it affects subdomains 3) More consistent use of domain names for clarity. 4) Using different heading sizes to show scope of section. Essentially, I added all the tidbits I had to clarify in getting this to work in my own example.

Introduction
============

This module checks the IP address of newly registered users against a
DNS block list. If a positive match is found, it gets logged.

Configuration
=============

  Option              Type     Default
  ------------------- -------- ------------
  registration\_rbl   string   *Required*