Update registry.md (#21001)

* Update registry.md

We will be deprecating the ability to push the deprecated format of v1 schema images on November 4th. We would like this message to show on this docs page on Oct 1st.

* Apply suggestions from code review

---------

Co-authored-by: Allie Sadler <[email protected]>

Author: sheltongraves

content/manuals/registry.md

@@ -39,6 +39,10 @@ aliases:
   - /registry/storage-drivers/swift/
 ---
 
+> [!IMPORTANT]
+>
+> The ability to push [deprecated Docker image manifest version 2, schema 1](https://distribution.github.io/distribution/spec/deprecated-schema-v1/) images to Docker Hub will be deprecated on November 4th, 2024.
+
 Registry, the open source implementation for storing and distributing container
 images and other content, has been donated to the CNCF. Registry now goes under
 the name of Distribution, and the documentation has moved to