feat(iam): add sentence

Author: ldecarvalho-doc

pages/iam/how-to/set-up-identity-federation.mdx

@@ -9,6 +9,10 @@ import Requirements from '@macros/iam/requirements.mdx'
 
 Scaleway supports Identity Federation to provide your teams with secure access to their accounts via Single Sign-On (SSO). Depending on your organization’s requirements, you can use either built-in OAuth2 providers or configure SAML for centralized identity management.
 
+<Message type="important">
+  SAML SSO login is in Early Access. This means that currenttly, only a few Organizations can access and test the feature.
+</Message>
+
 | Feature | **OAuth2** | **SAML** |
 |--------|-------------------------------|--------|
 | **Availability** | Enabled by default for all organizations | Available, but requires setup |