[docs] use SSO for MFA (#42084)

* mfa

* plans

docs/people-and-groups/start.md

@@ -28,12 +28,14 @@ Tell Metabase how long it should wait before asking people to log in again.
 
 Metabase offers several options for single sign-on (SSO) authentication.
 
-### SSO for Metabase Open Source Edition
+> If you need to set up 2-step or multi-factor authentication (2FA or MFA) for your Metabase, consider using one of the SSO options below.
+
+### SSO for Metabase Open Source and Starter plans
 
 - [Google Sign-in][google-sign-in]
 - [LDAP][ldap]
 
-### SSO for Metabase paid plans
+### SSO for Metabase Pro and Enterprise plans
 
 With some paid plans, you have more options to help orchestrate lots of people and groups.