container_manifest.yaml missing link to reference

https://github.com/GoogleCloudPlatform/deploymentmanager-samples/blob/56441d824ab7501e6adf65f9e65411976c978825/examples/v2/common/container_manifest.yaml#L16

This line points to a page that is not the reference documentation of container manifests. In fact, I couldn't find any specs for the container manifest anywhere and cannot guess which values are valid.