Update docs around what image formats are supported by GHCR (#806)

Author: Mark Phelps

content/packages/getting-started-with-github-container-registry/about-github-container-registry.md

@@ -8,19 +8,24 @@ versions:
 
 {% note %}
 
-**Note:** {% data variables.product.prodname_github_container_registry %} is currently in public beta and subject to change. Currently, {% data variables.product.prodname_github_container_registry %} only supports Docker image formats. During the beta, storage and bandwidth is free.
+**Note:** {% data variables.product.prodname_github_container_registry %} is currently in public beta and subject to change. During the beta, storage and bandwidth are free.
 
 {% endnote %}
 
-
 {% data reusables.package_registry.container-registry-feature-highlights %}
 
 To share context about your package's use, you can link a repository to your container image on {% data variables.product.prodname_dotcom %}. For more information, see "[Connecting a repository to a container image](/packages/managing-container-images-with-github-container-registry/connecting-a-repository-to-a-container-image)."
 
 ### Supported formats
 
-The {% data variables.product.prodname_container_registry %} currently only supports Docker images.
+The {% data variables.product.prodname_container_registry %} currently supports the following container image formats:
+
+* [Docker Image Manifest V2, Schema 2](https://docs.docker.com/registry/spec/manifest-v2-2/)
+* [Open Container Initiative (OCI) Specifications](https://github.com/opencontainers/image-spec)
+
+#### Manifest Lists/Image Indexes
 
+{% data variables.product.prodname_github_container_registry %} also supports [Docker Manifest List](https://docs.docker.com/registry/spec/manifest-v2-2/#manifest-list)/[OCI Image Index](https://github.com/opencontainers/image-spec/blob/79b036d80240ae530a8de15e1d21c7ab9292c693/image-index.md) formats which are defined in the Docker V2, Schema 2 and OCI image specifications.
 
 ### Visibility and access permissions for container images
 

content/packages/managing-container-images-with-github-container-registry/deleting-a-container-image.md

@@ -16,8 +16,6 @@ To delete a container image, you must have admin permissions to the container im
 
 When deleting public packages, be aware that you may break projects that depend on your package.
 
-
-
 ### Reserved package versions and names
 
 {% data reusables.package_registry.package-immutability %}

data/reusables/package_registry/container-registry-beta.md

@@ -1,5 +1,5 @@
 {% note %}
 
-**Note:** {% data variables.product.prodname_github_container_registry %} is currently in public beta and subject to change. Currently, {% data variables.product.prodname_github_container_registry %} only supports Docker image formats. During the beta, storage and bandwidth is free. For more information, see "[About {% data variables.product.prodname_github_container_registry %}](/packages/getting-started-with-github-container-registry/about-github-container-registry)."
+**Note:** {% data variables.product.prodname_github_container_registry %} is currently in public beta and subject to change. During the beta, storage and bandwidth are free. For more information, see "[About {% data variables.product.prodname_github_container_registry %}](/packages/getting-started-with-github-container-registry/about-github-container-registry)."
 
 {% endnote %}