update readme for docker container registry url

Author: Qingping Hou

README.md

@@ -50,7 +50,7 @@ Simply download the prebuilt single binary from [release page](https://github.co
 go get github.com/scribd/objinsync
 ```
 
-An officially maintained public docker image is available at https://hub.docker.com/repository/docker/scribdinc/objinsync.
+Pre-built docker images are available at https://github.com/orgs/scribd/packages/container/package/objinsync.
 
 
 Development