Override OIDC provider discovered claims

Update the doc after merging dexidp/dex#3267

Signed-off-by: Maksim Nabokikh <[email protected]>

content/docs/connectors/oidc.md

@@ -106,6 +106,17 @@ connectors:
       # The set claim is used as groups.
       # Default: groups
       # groups: "cognito:groups"
+
+	  # The section to override options discovered automatically from
+	  # the providers' discovery URL (.well-known/openid-configuration).
+    providerDiscoveryOverrides
+      # tokenURL provides a way to user overwrite the token URL
+	    # from the .well-known/openid-configuration 'token_endpoint'.
+      # tokenURL: ""
+      #
+	    # authURL provides a way to user overwrite the authorization URL
+	    # from the .well-known/openid-configuration 'authorization_endpoint'.   
+      # authURL: ""
 ```
 
 [oidc-doc]: openid-connect.md