Instead of setting the --registry flag to search a single registry,
prefix the registry before the image name in the input, an example is
`podman search registry.fedoraproject.org/fedora` and this will search for
the fedora image in only registry.fedoraproject.org.
Signed-off-by: umohnani8 <umohnani@redhat.com>
Closes: #1011
Approved by: rhatdan