update pgouser file information

Author: xenophenes

hugo/content/installation/configuration.adoc

@@ -79,8 +79,9 @@ $COROOT/conf/apiserver/pgouser
 
 The sample configuration for `pgouser` is as follows -
 ....
-username:password
-testuser:testpass
+username:password:pgoadmin
+testuser:testpass:pgoadmin
+readonlyuser:testpass:pgoreader
 ....
 
 Modify these values to be unique to your environment.

hugo/content/installation/deployment.adoc

@@ -58,7 +58,7 @@ export PGO_CLIENT_CERT=$COROOT/conf/apiserver/server.crt
 export PGO_CLIENT_KEY=$COROOT/conf/apiserver/server.key
 ....
 
-The pgo client uses Basic Authentication to authenticate to the operator REST API, for authentication, add the following `.pgouser` file to your $HOME -
+The pgo client uses Basic Authentication to authenticate to the operator REST API. For authentication, add the following `.pgouser` file to your $HOME -
 ....
 echo "username:password" > $HOME/.pgouser
 ....