Update _index.md (#5429)
Update _index.md (#5429)

URL for arm64 is missing the 64 suffix.
GoogleContainerTools/skaffold,GoogleContainerTools/skaffold,GoogleContainerTools/skaffold,GoogleContainerTools/skaffold,GoogleContainerTools/skaffold,GoogleContainerTools/skaffold,GoogleContainerTools/skaffold,GoogleContainerTools/skaffold,GoogleContainerTools/skaffold