DOCSP-38904 fed auth intro update (#72)

* fed auth intro update

Author: kyuan-mongodb

source/ak8so-configure-federated-authentication.txt

@@ -1,8 +1,8 @@
 .. _ak8so-federated-auth:
 
-==================================================
-Configure Federated Authentication from Kubernetes
-==================================================
+=================================================
+Leverage Federated Authentication from Kubernetes
+=================================================
 
 .. default-domain:: mongodb
 
@@ -12,8 +12,18 @@ Configure Federated Authentication from Kubernetes
    :depth: 1
    :class: singlecol
 
-|ak8so| supports configuring :ref:`federated authentication
-<atlas-federated-authentication>` for your |service| organization.
+|ak8so| supports using :ref:`federated authentication
+<atlas-federated-authentication>` for your |service| organization. 
+
+.. note:: 
+
+   You can't use |ak8so| to set up an |idp|. To set up an |idp|, see
+   :atlas:`Configure Database Deployment Authentication and
+   Authorization </security/config-db-auth>`.  
+   
+   Once you set up your |idp|, you can manage the role mappings that
+   authenticate users to use your |idp|.
+
 To configure federated authentication through the |ak8so|, you must 
 specify and update the :ref:`atlasfederatedauth-custom-resource`.