Update attributes sync on JWT (#29602)

* Update attributes sync on JWT

* Update docs/people-and-groups/authenticating-with-jwt.md

Co-authored-by: Natalie <nat@metabase.com>

---------

Co-authored-by: Natalie <nat@metabase.com>

docs/people-and-groups/authenticating-with-jwt.md

@@ -21,7 +21,7 @@ Metabase supports two auth flows that can be used with JWT:
 
 Metabase's auth flows are custom workflows modelled after OAuth 2.0. You can use the auth flow with PKCE to incorporate random keys generated on demand.
 
-Currently, the only algorithm Metabase supports is [HS256](https://en.wikipedia.org/wiki/JSON_Web_Token) ([HMAC](https://en.wikipedia.org/wiki/HMAC) + [SHA-256](https://en.wikipedia.org/wiki/SHA-2).
+Currently, the only algorithm Metabase supports is [HS256](https://en.wikipedia.org/wiki/JSON_Web_Token) ([HMAC](https://en.wikipedia.org/wiki/HMAC) + [SHA-256](https://en.wikipedia.org/wiki/SHA-2)).
 
 ## Typical flow for a JWT-based SSO interaction with Metabase
 
@@ -56,6 +56,8 @@ These are additional settings you can fill in to pass user attributes to Metabas
 - **First Name attribute:** the key to retrieve each JWT user's first name.
 - **Last Name attribute:** if you guessed that this is the key to retrieve each JWT user's last name, well then you have been paying attention.
 
+You can send additional user attributes to Metabase by adding the attributes as key/value pairs to your JWT. These attributes will be synced on every login.
+
 ## Group schema
 
 You can use your JWT to assign Metabase users to custom groups by following these steps: