Add allowed_scopes to README

Author: nsklikas

docs/source/contents/conf.rst

@@ -54,7 +54,6 @@ sub_funcs
 Optional. Functions involved in *sub*ject value creation.
 
 
-
 scopes_mapping
 ##############
 
@@ -75,6 +74,12 @@ allowed_scopes
 A list with the scopes that are allowed to be used (defaults to the keys in scopes_mapping).
 
 
+advertised_scopes
+#################
+
+A list with the scopes that will be advertised in the well-known endpoint (defaults to allowed_scopes).
+
+
 ------
 add_on
 ------