zstd is a compression algorithm that has a very fast decoder, while
providing also good compression ratios. The fast decoder makes it
suitable for container images, as decompressing the tarballs is a very
expensive operation.
https://github.com/opencontainers/image-spec/pull/788 added support
for zstd to the OCI image specs.
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
