Add instruction about the profile scope needed to get the preferred u…

…sername claim from GitHub

docs/hub-deployment-guide/configure-auth/cilogon.md

@@ -129,14 +129,15 @@ The steps to enable the JupyterHub CILogonOAuthenticator for a hub are similar w
     3. **Authenticate using GitHub with CILogon**:
 
         *This example sets the GitHub nickname as the Hub username using the `username_claim` option*
-
         ```yaml
         jupyterhub:
           hub:
             config:
               JupyterHub:
                 authenticator_class: cilogon
               CILogonOAuthenticator:
+                scope:
+                  - "profile"
                 oauth_callback_url: https://{{ HUB_DOMAIN }}/hub/oauth_callback
                 shown_idps:
                   - http://github.com/login/oauth/authorize