Group name as per hosts.origin.example

The example inventory file does not currently work and fails with:

PLAY [Gather Cluster facts] ***************************************************
skipping: no hosts matched

PLAY RECAP ********************************************************************

this is because the group name is actually OSEv3 (inline with https://github.com/openshift/openshift-ansible/blob/master/inventory/byo/hosts.origin.example#L4) and not OSv3.

Also added references to inventory/byo/hosts.[origin,ose,aep].example for more complete examples.

README_AEP.md

@@ -98,6 +98,8 @@ aep3-node[1:2].example.com
 The hostnames above should resolve both from the hosts themselves and
 the host where ansible is running (if different).
 
+A more complete example inventory file ([hosts.aep.example](https://github.com/openshift/openshift-ansible/blob/master/inventory/byo/hosts.aep.example)) is available under the [`/inventory/byo`](https://github.com/openshift/openshift-ansible/tree/master/inventory/byo) directory.
+
 ## Running the ansible playbooks
 From the openshift-ansible checkout run:
 ```sh

README_OSE.md

@@ -105,6 +105,8 @@ ose3-node[1:2].example.com
 The hostnames above should resolve both from the hosts themselves and
 the host where ansible is running (if different).
 
+A more complete example inventory file ([hosts.ose.example](https://github.com/openshift/openshift-ansible/blob/master/inventory/byo/hosts.ose.example)) is available under the [`/inventory/byo`](https://github.com/openshift/openshift-ansible/tree/master/inventory/byo) directory.
+
 ## Running the ansible playbooks
 From the openshift-ansible checkout run:
 ```sh

README_origin.md

@@ -59,12 +59,12 @@ option to ansible-playbook.
 # This is an example of a bring your own (byo) host inventory
 
 # Create an OSEv3 group that contains the masters and nodes groups
-[OSv3:children]
+[OSEv3:children]
 masters
 nodes
 
 # Set variables common for all OSEv3 hosts
-[OSv3:vars]
+[OSEv3:vars]
 
 # SSH user, this user should allow ssh based auth without requiring a password
 ansible_ssh_user=root
@@ -95,6 +95,8 @@ osv3-lb.example.com
 The hostnames above should resolve both from the hosts themselves and
 the host where ansible is running (if different).
 
+A more complete example inventory file ([hosts.origin.example](https://github.com/openshift/openshift-ansible/blob/master/inventory/byo/hosts.origin.example)) is available under the [`/inventory/byo`](https://github.com/openshift/openshift-ansible/tree/master/inventory/byo) directory.
+
 ## Running the ansible playbooks
 From the openshift-ansible checkout run:
 ```sh