Last batch change approvers to reviewers (#8644)

This is meant to be the last change for issue #7432.

Closes:# 7432

content/en/docs/reference/kubectl/cheatsheet.md

@@ -1,10 +1,10 @@
 ---
-approvers:
+title: kubectl Cheat Sheet
+reviewers:
 - bgrant0607
 - erictune
 - krousey
 - clove
-title: kubectl Cheat Sheet
 ---
 
 See also: [Kubectl Overview](/docs/reference/kubectl/overview/) and [JsonPath Guide](/docs/reference/kubectl/jsonpath).

content/en/docs/reference/kubectl/conventions.md

@@ -1,8 +1,8 @@
 ---
-approvers:
+title: kubectl Usage Conventions
+reviewers:
 - bgrant0607
 - janetkuo
-title: kubectl Usage Conventions
 ---
 
 {{< toc >}}

content/en/docs/reference/kubectl/docker-cli-to-kubectl.md

@@ -1,9 +1,9 @@
 ---
-approvers:
+title: kubectl for Docker Users
+reviewers:
 - bgrant0607
 - brendandburns
 - thockin
-title: kubectl for Docker Users
 ---
 
 You can use the Kubernetes command line tool kubectl to interact with the api. You can use kubectl if you are familiar with docker-cli. However, there are a few differences in the docker-cli commands and the kubectl commands. Each of the following section details a docker subcommand and explains the kubectl equivalent.

content/en/docs/reference/kubectl/overview.md

@@ -1,5 +1,5 @@
 ---
-approvers:
+reviewers:
 - bgrant0607
 - hw-qiaolei
 title: Overview of kubectl