Update designs/discontinue_usage_of_kube_rbac_proxy.md

Co-authored-by: Joe Julian <me@joejulian.name>

designs/discontinue_usage_of_kube_rbac_proxy.md

@@ -53,7 +53,7 @@ such as Calico, Cilium, WeaveNet, and Canal, shows to offer  support for Network
 > We tried to do that, see [here](https://github.com/kubernetes/test-infra/blob/master/config/jobs/image-pushing/k8s-staging-kubebuilder.yaml) the recipe implemented.
 > However, it does not work because kube-rbac-proxy is not under the
 > kubernetes umbrella. More over we experiment the GitHub Repository as alternative approach, see the [PR](https://github.com/kubernetes-sigs/kubebuilder/pull/3854) but seems
-> that we are not allowed to use it. Nevertheless, both approaches does not show to sort out all motivations and requirements
+> that we are not allowed to use it. Nevertheless, neither approach sorts out all motivations and requirements
 > Ideally, Kubebuilder should not be responsible for maintain and promote third-part artifacts.
 
 1. However, is not Kubebuilder also building and promoting the binaries required to be used within [EnvTest](./../docs/book/src/reference/envtest.md)