Add application cred change note to ShiftStack install-config params

Author: maxwelldb

modules/installation-configuration-parameters.adoc

@@ -839,8 +839,10 @@ Additional {rh-openstack} configuration parameters are described in the followin
 |A list of strings, for example `["zone-1", "zone-2"]`.
 
 |`platform.openstack.cloud`
-|The name of the {rh-openstack} cloud to use from the list of clouds in the
-`clouds.yaml` file.
+|The name of the {rh-openstack} cloud to use from the list of clouds in the `clouds.yaml` file.
+
+In the cloud configuration in the `clouds.yaml` file, if possible, use application credentials rather than a user name and password combination. Using application credentials avoids disruptions from secret propogation that follow user name and password rotation. 
+
 |String, for example `MyCloud`.
 
 |`platform.openstack.externalNetwork`