Fix minor spelling errors in containertools README
Fix minor spelling errors in containertools README

Signed-off-by: Jens Dieskau <21e2afd93d5ce53123476032b5dca8a79b546094@dieskau.pm>

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