Backport #2041 to 3.13

Author: michaelklishin

docs/oauth2.md

@@ -564,7 +564,8 @@ By default, RabbitMQ searches for the `sub` claim first, and if it is not found,
 Most authorization servers return the user's GUID in the `sub` claim instead of the user's username or email address, anything the user can relate to. When the `sub` claim does not carry a *user-friendly username*, you can configure one or several claims to extract the username from the token.
 
 Example `rabbitmq.conf` configuration:
-```
+
+``` ini
 # ...
 auth_oauth2.resource_server_id = rabbitmq
 auth_oauth2.preferred_username_claims.1 = user_name

versioned_docs/version-3.13/oauth2.md

@@ -563,14 +563,14 @@ By default, RabbitMQ searches for the `sub` claim first, and if it is not found,
 
 Most authorization servers return the user's GUID in the `sub` claim instead of the user's username or email address, anything the user can relate to. When the `sub` claim does not carry a *user-friendly username*, you can configure one or several claims to extract the username from the token.
 
-Example `advanced.config` configuration:
-
-```
-  ...
-  {rabbitmq_auth_backend_oauth2, [
-    {resource_server_id, <<"rabbitmq">>},
-    {preferred_username_claims, [<<"user_name">>,<<"email">>]},
-  ...
+Example `rabbitmq.conf` configuration:
+
+``` ini
+# ...
+auth_oauth2.resource_server_id = rabbitmq
+auth_oauth2.preferred_username_claims.1 = user_name
+auth_oauth2.preferred_username_claims.2 = email
+# ...
 ```
 
 In the example configuration, RabbitMQ searches for the `user_name` claim first and if it is not found, RabbitMQ searches for the `email`. If these are not found, RabbitMQ uses its default lookup mechanism which first looks for `sub` and then `client_id`.