Specify version = 2 & fix wrong key in registry.md (GCR example)
Specify version = 2 & fix wrong key in registry.md (GCR example)

Signed-off-by: Takumasa Sakao <d0d91f4c45c74b6b7f7a5664a936a92148094676@gmail.com>

containerd/containerd,dmcgowan/containerd,vdemeester/containerd,vdemeester/containerd,estesp/containerd,dmcgowan/containerd,thaJeztah/containerd,containerd/containerd,estesp/containerd,thaJeztah/containerd,mikebrow/containerd,mikebrow/containerd