docs(srv): update doc with new auth methods MTA-6708

Author: SamyOubouaziz

pages/serverless-containers/concepts.mdx

@@ -161,7 +161,7 @@ Refer to the [dedicated documentation](/serverless-containers/reference-content/
 
 A container's privacy policy defines whether a container may be invoked anonymously (**public**) or only via an authentication mechanism provided by the [Scaleway API](https://www.scaleway.com/en/developers/api/serverless-containers/#authentication) (**private**).
 
-### JWT Token
+### JWT Token (legacy)
 
 JWT (JSON Web Token) is an access token you can create to enable an application to access your `private` container. [Find out how to restrict access to a container](/serverless-containers/how-to/secure-a-container/#restrict-access-to-your-containers).