7533d70ada
`CPUCFSQuotaPeriod` Feature Gate is set from the flag name `CustomCPUCFSQuotaPeriod` per [`kube_features.go#163`](https://github.com/kubernetes/kubernetes/blob/master/pkg/features/kube_features.go#L163) This PR updates the docs to suit. In some respects it would be tidier to remove `Custom` prefix from `kube_features.go` so that the Feature Gate naming maps 1:1. Happy to close this PR and do PR to remove 'Custom' prefix instead.