Use registry.example.com as example default registry

Signed-off-by: Jason Hall <jasonhall@redhat.com>

annotations.md

@@ -45,7 +45,7 @@ This specification defines the following annotation keys, intended for but not l
   * This SHOULD NOT reference any other images used to generate the contents of the image (e.g., multi-stage Dockerfile builds).
 * **org.opencontainers.image.base.name** Image reference of the image this image is based on (string)
   * This SHOULD be image references in the format defined by [distribution/distribution](https://github.com/distribution/distribution/blob/d0deff9cd6c2b8c82c6f3d1c713af51df099d07b/reference/reference.go).
-  * This SHOULD be a fully qualified reference name, without any assumed default registry. (e.g., `index.docker.io/my-org/my-image:tag` instead of `my-org/my-image:tag`).
+  * This SHOULD be a fully qualified reference name, without any assumed default registry. (e.g., `registry.example.com/my-org/my-image:tag` instead of `my-org/my-image:tag`).
   * This SHOULD be the immediate image sharing zero-indexed layers with the image, such as from a Dockerfile `FROM` statement.
   * This SHOULD NOT reference any other images used to generate the contents of the image (e.g., multi-stage Dockerfile builds).
   * If the `image.base.name` annotation is specified, the `image.base.digest` annotation SHOULD be the digest of the manifest referenced by the `image.ref.name` annotation.