sentence added about Schema 2 format

Author: dlepow

articles/container-registry/container-registry-image-formats.md

@@ -19,7 +19,7 @@ Use a private repository in Azure Container Registry to manage one of the follow
 
 * [Docker Image Manifest V2, Schema 1](https://docs.docker.com/registry/spec/manifest-v2-1/)
 
-* [Docker Image Manifest V2, Schema 2](https://docs.docker.com/registry/spec/manifest-v2-2/)
+* [Docker Image Manifest V2, Schema 2](https://docs.docker.com/registry/spec/manifest-v2-2/) - includes Manifest Lists which allow registries to store multiplatform images under a single "image:tag" reference
 
 * [Open Container Initiative (OCI) Image Format Specification](https://github.com/opencontainers/image-spec/blob/master/spec.md)