Add package install descriptions
Add package install descriptions

We need to simply describe how to install a packaged
version of buildah for each distribution, rather then
just describing how to build it.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

Closes: #1310
Approved by: TomSweeneyRedHat

nalind/buildah-1,projectatomic/buildah,projectatomic/buildah,nalind/buildah,TomSweeneyRedHat/buildah,rhatdan/buildah,rhatdan/buildah,TomSweeneyRedHat/buildah,nalind/buildah-1,nalind/buildah-1,nalind/buildah,rhatdan/buildah,projectatomic/buildah,TomSweeneyRedHat/buildah