update readme to include kube-api oidc config

[tweeks024]

found this info in the video and thought I'd put it in the readme as well

[mlbiam]

I didn't put this in there because these steps are custom created for each deployment. For instance if your OU_HOST was for k8s.myhost.dev the first line would be - --oidc-issuer-url=https://k8s.myhost.dev/auth/idp/k8sIdp . I wanted to keep folks from copying and pasting directly from the README. wdyt about changing the "Complete SSO Integration with Kubernetes" to make it clearer?

[tweeks024]

@mlbiam that makes much more sense, I updated the text under "Complete SSO Integration with Kubernetes" trying to keep it generic, let me know what you think