DOC - Adopting the common role documentation pattern

As discussed during the Newton design summit, we
agreed to adopt the role documentation pattern laid
out in the os_keystone role

Change-Id: Ie09f55b57361a7d5ce0c8cb987f7cfdaa81961ae

README.rst

@@ -1,9 +1,22 @@
-OpenStack LXC host setup
-########################
-:tags: openstack, lxc, host, cloud, ansible
-:category: \*nix
+OpenStack-Ansible LXC hosts
+###########################
 
-Role for deployment and setup of an LXC host.
+Ansible role that configures a host for running LXC containers.
+
+Default Variables
+=================
+
+.. literalinclude:: ../../defaults/main.yml
+   :language: yaml
+   :start-after: under the License.
+
+Required Variables
+==================
+
+None
+
+Example Playbook
+================
 
 .. code-block:: yaml
 
@@ -11,4 +24,4 @@ Role for deployment and setup of an LXC host.
       hosts: "hosts"
       user: root
       roles:
-        - { role: "lxc_hosts", tags: [ "lxc-host", "host-setup" ] }
+        - { role: "lxc_hosts" }

doc/source/index.rst

@@ -1,23 +1 @@
-lxc_host role docs
-==================
-
-The lxc_host role is used to setup hosts that will be running LXC
-within them. The role will configure and build everything needed
-for the environment to be successful in deploying LXC containers.
-
-In the example the role is using an optional argument to create an
-LXC cached image on the disk. The use of this extra variable will
-download an image into place and update it.
-
-
-Basic Role Example
-^^^^^^^^^^^^^^^^^^
-
-.. code-block:: yaml
-
-    - role: "lxc_host"
-      lxc_container_caches:
-        - url: "{{ repo_pip_default_index | netorigin }}/container_images/rpc-trusty-container.tgz"
-          name: "trusty.tgz"
-          sha256sum: "56c6a6e132ea7d10be2f3e8104f47136ccf408b30e362133f0dc4a0a9adb4d0c"
-          chroot_path: trusty/rootfs-amd64
+.. include:: ../../README.rst