Add roles to README

Author: markgoddard

README.md

@@ -6,4 +6,13 @@ This collection includes content for interacting with OpenStack clouds.
 
 ### Roles
 
-- [os_openstacksdk](roles/os_openstacksdk): Install `openstacksdk` Python package
+- [os_container_clusters](roles/os_container_clusters)
+- [os_deploy_templates](roles/os_deploy_templates)
+- [os_flavors](roles/os_flavors)
+- [os_host_aggregates](roles/os_host_aggregates)
+- [os_images](roles/os_images)
+- [os_networks](roles/os_networks)
+- [os_openstackclient](roles/os_openstackclient)
+- [os_openstacksdk](roles/os_openstacksdk)
+- [os_projects](roles/os_projects)
+- [os_volumes](roles/os_volumes)