completions: Introduce transports completions
completions: Introduce transports completions

Introduces bash completions for transports which commands (copy, delete,
and inspect) support.

Signed-off-by: ERAMOTO Masaya <495370e91cae577581028a5efee5824f74357ca0@jp.fujitsu.com>

mtrmac/skopeo,mtrmac/skopeo,mtrmac/skopeo