Fix relative links issue in zh content (#13312)

* `http://kubernetes.io/docs/` -> `/docs/`

* `https://kubernetes.io/docs/` -> `/docs/`

content/zh/docs/tasks/service-catalog/install-service-catalog-using-sc.md

@@ -32,7 +32,7 @@ Use the [Service Catalog Installer](https://github.com/GoogleCloudPlatform/k8s-s
 * Install [Go 1.6+](https://golang.org/dl/) and set the `GOPATH`.
 * Install the [cfssl](https://github.com/cloudflare/cfssl) tool needed for generating SSL artifacts.
 * Service Catalog requires Kubernetes version 1.7+.
-* [Install and setup kubectl](https://kubernetes.io/docs/tasks/tools/install-kubectl/) so that it is configured to connect to a Kubernetes v1.7+ cluster.
+* [Install and setup kubectl](/docs/tasks/tools/install-kubectl/) so that it is configured to connect to a Kubernetes v1.7+ cluster.
 * The kubectl user must be bound to the *cluster-admin* role for it to install Service Catalog. To ensure that this is true, run the following command:
 
         kubectl create clusterrolebinding cluster-admin-binding --clusterrole=cluster-admin --user=<user-name>
@@ -41,7 +41,7 @@ Use the [Service Catalog Installer](https://github.com/GoogleCloudPlatform/k8s-s
 * 安装 [Go 1.6+](https://golang.org/dl/) 以及设置 `GOPATH`。
 * 安装生成 SSL 工件所需的 [cfssl](https://github.com/cloudflare/cfssl) 工具。
 * 服务目录需要 Kubernetes 1.7+ 版本。
-* [安装和设置 kubectl](https://kubernetes.io/docs/tasks/tools/install-kubectl/)，以便将其配置为连接到 Kubernetes v1.7+ 集群。
+* [安装和设置 kubectl](/docs/tasks/tools/install-kubectl/)，以便将其配置为连接到 Kubernetes v1.7+ 集群。
 * 要安装服务目录，kubectl 用户必须绑定到 *cluster-admin* 角色。为了确保这是正确的，请运行以下命令：
 
         kubectl create clusterrolebinding cluster-admin-binding --clusterrole=cluster-admin --user=<user-name>