Use git.openstack.org everywhere

Our official git master is at git.openstack.org, update places
that use github instead.

Also, update content to point to main page, the user guide is not in
DocBook anymore.

Also, remove some mention of Rackspace, they do not use this anymore.

Change-Id: Ic63d95bcd409ccd58255e21a2098683d70c6b83f

README.rst

@@ -1,25 +1,21 @@
 Introduction
 ============
 
-This project is the Rackspace/OpenStack customization of the Docbkx
-plug-in for creating documentation artifacts for Rackspace, OpenStack,
-and other OpenStack projects.
+This project is the OpenStack customization of the Docbkx
+plug-in for creating documentation artifacts for OpenStack.
 
 Example output
 ==============
-Rackspace output: 
-
-- http://docs.rackspace.com/files/api/v1/cf-devguide/content/Overview-d1e70.html
 
 OpenStack output:
 
-- http://docs.openstack.org/user-guide/content/
+- http://docs.openstack.org/
 - http://api.openstack.org/api-ref.html
 
 OpenStack source files:
 
-- https://github.com/openstack/openstack-manuals/tree/master/doc/user-guide/src
-- https://github.com/openstack/api-site/tree/master/api-ref
+- https://git.openstack.org/cgit/openstack/openstack-manuals
+- https://git.openstack.org/cgit/openstack/api-site
 
 
 Test changes to clouddocs-maven-plugin
@@ -32,7 +28,7 @@ To test changes to clouddocs-maven-plugin on your local machine:
 
 #. Run this command to clone clouddocs-maven-plugin:
 
-        git clone git@github.com:openstack/clouddocs-maven-plugin.git
+        git clone https://git.openstack.org/openstack/clouddocs-maven-plugin
 
 #. CD into the clouddocs-maven-plugin directory.
 
@@ -47,7 +43,7 @@ To test changes to clouddocs-maven-plugin on your local machine:
 
 #. Run this command to clone the api-site:
 
-        git clone git@github.com:openstack/api-site.git
+        git clone https://git.openstack.org/openstack/api-site
 
 #. CD into the api-site directory.