OAuth: custom username docs (#28400)

* OAuth: more user-frienly logging

* OAuth: custom user name attribute

* OAuth: remove deprecated nameAttributeName option

* OAuth: nameAttributePath tests

* OAuth: add name_attribute_path config option

* OAuth: docs for name_attribute_path option

* OAuth: docs for name_attribute_path

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>

docs/sources/auth/generic-oauth.md

@@ -75,6 +75,10 @@ Customize user login using `login_attribute_path` configuration option. Order of
 
 You can customize the attribute name used to extract the ID token from the returned OAuth token with the `id_token_attribute_name` option.
 
+You can set the user's display name with JMESPath using the `name_attribute_path` configuration option. It operates the same way as the `login_attribute_path` option.
+
+> **Note:** `name_attribute_path` is available in Grafana 7.4+.
+
 ## Set up OAuth2 with Auth0
 
 1. Create a new Client in Auth0