Switch language name 'zh' to 'zh-cn'

This is the first step to rename 'zh' to 'zh-cn'. There are several reasons why we rename the language name.

- The upstream docsy theme changed the language name, leading to many warnings during site build;
  The side-effect is that the i18n strings are no longer working.
- We believe renaming the language is the right thing to do, because this move can make room for other variants of Chinese language, such as 'zh-tw', 'zh-sg' etc.

There would be several follow-ups to this PR, such as fixing the intra-site links, adding redirects etc.

We will lock up changes to zh/zh-cn pages for the moment, until this one gets in.

This PR is based on commit cdad0a7342.

content/zh-cn/docs/tasks/administer-cluster/developing-cloud-controller-manager.md

@@ -0,0 +1,85 @@
+---
+title: 开发云控制器管理器
+content_type: task
+---
+
+<!--
+reviewers:
+- luxas
+- thockin
+- wlan0
+title: Developing Cloud Controller Manager
+content_type: concept
+-->
+
+<!-- overview -->
+
+{{< feature-state for_k8s_version="v1.11" state="beta" >}}
+
+{{< glossary_definition term_id="cloud-controller-manager" length="all">}}
+
+<!-- body -->
+
+<!--
+## Background
+
+Since cloud providers develop and release at a different pace compared to the Kubernetes project, abstracting the provider-specific code to the `cloud-controller-manager` binary allows cloud vendors to evolve independently from the core Kubernetes code.
+-->
+## 背景
+
+由于云驱动的开发和发布与 Kubernetes 项目本身步调不同，将特定于云环境的代码抽象到
+`cloud-controller-manager` 二进制组件有助于云厂商独立于 Kubernetes
+核心代码推进其驱动开发。
+
+<!--
+The Kubernetes project provides skeleton cloud-controller-manager code with Go interfaces to allow you (or your cloud provider) to plug in your own implementations. This means that a cloud provider can implement a cloud-controller-manager by importing packages from Kubernetes core; each cloudprovider will register their own code by calling `cloudprovider.RegisterCloudProvider` to update a global variable of available cloud providers.
+-->
+Kubernetes 项目提供 cloud-controller-manager 的框架代码，其中包含 Go 语言的接口，
+便于你（或者你的云驱动提供者）接驳你自己的实现。这意味着每个云驱动可以通过从
+Kubernetes 核心代码导入软件包来实现一个 cloud-controller-manager；
+每个云驱动会通过调用 `cloudprovider.RegisterCloudProvider` 接口来注册其自身实现代码，
+从而更新一个用来记录可用云驱动的全局变量。
+
+<!--
+## Developing
+-->
+## 开发
+
+### 树外（Out of Tree）
+
+<!--
+To build an out-of-tree cloud-controller-manager for your cloud, follow these steps:
+-->
+要为你的云环境构建一个树外（Out-of-Tree）云控制器管理器：
+
+<!--
+1. Create a go package with an implementation that satisfies [cloudprovider.Interface](https://github.com/kubernetes/cloud-provider/blob/master/cloud.go).
+2. Use [main.go in cloud-controller-manager](https://github.com/kubernetes/kubernetes/blob/master/cmd/cloud-controller-manager/main.go) from Kubernetes core as a template for your main.go. As mentioned above, the only difference should be the cloud package that will be imported.
+3. Import your cloud package in `main.go`, ensure your package has an `init` block to run [cloudprovider.RegisterCloudProvider](https://github.com/kubernetes/cloud-provider/blob/master/plugins.go).
+-->
+1. 使用满足 [`cloudprovider.Interface`](https://github.com/kubernetes/cloud-provider/blob/master/cloud.go)
+   接口的实现来创建一个 Go 语言包。
+2. 使用来自 Kubernetes 核心代码库的
+   [cloud-controller-manager 中的 main.go](https://github.com/kubernetes/kubernetes/blob/master/cmd/cloud-controller-manager/main.go)
+   作为 `main.go` 的模板。如上所述，唯一的区别应该是将导入的云包不同。
+3. 在 `main.go` 中导入你的云包，确保你的包有一个 `init` 块来运行
+   [`cloudprovider.RegisterCloudProvider`](https://github.com/kubernetes/cloud-provider/blob/master/plugins.go)。
+
+<!--
+Many cloud providers publish their controller manager code as open source. If you are creating
+a new cloud-controller-manager from scratch, you could take an existing out-of-tree cloud
+controller manager as your starting point.
+-->
+很多云驱动都将其控制器管理器代码以开源代码的形式公开。
+如果你在开发一个新的 cloud-controller-manager，你可以选择某个树外（Out-of-Tree）
+云控制器管理器作为出发点。
+
+### 树内（In Tree）
+
+<!--
+For in-tree cloud providers, you can run the in-tree cloud controller manager as a {{< glossary_tooltip term_id="daemonset" >}} in your cluster. See [Cloud Controller Manager Administration](/docs/tasks/administer-cluster/running-cloud-controller/) for more details.
+-->
+对于树内（In-Tree）驱动，你可以将树内云控制器管理器作为集群中的
+{{< glossary_tooltip term_id="daemonset" text="DaemonSet" >}} 来运行。
+有关详细信息，请参阅[云控制器管理器管理](/zh/docs/tasks/administer-cluster/running-cloud-controller/)。
+