docs: CNI versioning for 0.3.0 upgrade
docs: CNI versioning for 0.3.0 upgrade

mcastelino/cni,rosenhouse/cni,squeed/plugins,dcbw/cni,appc/cni,rosenhouse/cni,appc/cni,dcbw/cni,tangle329/cni,kad/cni,containernetworking/plugins,kad/cni,squeed/plugins,containernetworking/cni,mcastelino/cni,tangle329/cni,containernetworking/plugins,containernetworking/cni