add comment to interfaces
add comment to interfaces

Signed-off-by: Antonio Murdaca <f9809039ea4850e75dcb8d80b778844aa463358f@redhat.com>

mtrmac/skopeo,projectatomic/skopeo,containers/image,mikebrow/skopeo,containers/image,mtrmac/skopeo,jwhonce/skopeo,masters-of-cats/image,projectatomic/skopeo,jwhonce/skopeo,mikebrow/skopeo,mtrmac/skopeo