update kubeadm-kubelet documentation to reflect CNI package change

[neolit123]

the kubernetes-cni contents (plugins) will now be bundled as part of the kubelet package:
kubernetes/release#1330
the kubernetes-cni package will be removed.

the action item here is to remove:

kubernetes-cni

from this list:
https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/kubelet-integration/#kubernetes-binaries-and-package-contents

and update the item:

kubelet

to have the description:

Installs the kubelet binary in /usr/bin and CNI binaries in /opt/cni/bin.

file location:
https://github.com/kubernetes/website/blob/master/content/en/docs/setup/production-environment/tools/kubeadm/kubelet-integration.md

/priority important-longterm
/kind documentation
/help
/good-first-issue

[k8s-ci-robot]

@neolit123:
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Please ensure the request meets the requirements listed here.

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In response to this:

the kubernetes-cni contents (plugins) will now be bundled as part of the kubelet package:
kubernetes/release#1330
the kubernetes-cni package will be removed.

the action item here is to remove:

kubernetes-cni

from this list:
https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/kubelet-integration/#kubernetes-binaries-and-package-contents

/priority important-longterm
/kind documentation
/help
/good-first-issue

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[helenfeng737]

/assign

[justaugustus]

FYI, changes should only be staged, and not merged until after the next set of patch releases goes out: https://github.com/kubernetes/sig-release/blob/master/releases/patch-releases.md