Add note about role search path.

docsite/latest/rst/playbooks_roles.rst

@@ -194,6 +194,9 @@ This designates the following behaviors, for each role 'x':
 - Any copy tasks can reference files in roles/x/files/ without having to path them relatively or absolutely
 - Any script tasks can reference scripts in roles/x/files/ without having to path them relatively or absolutely
 - Any template tasks can reference files in roles/x/templates/ without having to path them relatively or absolutely
+   
+In Ansible 1.4 and later you can configure a roles_path to search for roles.  Use this to check all of your common roles out to one location, and share
+them easily between multiple playbook projects.  See :doc:`intro_configuration` for details about how to set this up in ansible.cfg.
 
 .. note::
    Role dependencies are discussed below.