en: update pd config; link deployment docs (#1012)

Signed-off-by: Ran <huangran@pingcap.com>

en/configure-a-tidb-cluster.md

@@ -390,7 +390,8 @@ For all the configurable parameters of PD, refer to [PD Configuration File](http
 
 > **Note:**
 >
-> If you deploy your TiDB cluster using CR, make sure that `Config: {}` is set, no matter you want to modify `config` or not. Otherwise, PD components might not be started successfully. This step is meant to be compatible with `Helm` deployment.
+> - If you deploy your TiDB cluster using CR, make sure that `Config: {}` is set, no matter you want to modify `config` or not. Otherwise, PD components might not be started successfully. This step is meant to be compatible with `Helm` deployment.
+> - After the cluster is started for the first time, some PD configuration items are persisted in etcd. The persisted configuration in etcd takes precedence over that in PD. Therefore, after the first start, you cannot modify some PD configuration using parameters. You need to dynamically modify the configuration using SQL statements, pd-ctl, or PD server API. Currently, among all the configuration items listed in [Modify PD configuration online](https://docs.pingcap.com/tidb/stable/dynamic-config#modify-pd-configuration-online), except `log.level`, all the other configuration items cannot be modified using parameters after the first start.
 
 #### Configure TiFlash parameters
 

en/deploy-on-alibaba-cloud.md

@@ -8,6 +8,8 @@ aliases: ['/docs/tidb-in-kubernetes/dev/deploy-on-alibaba-cloud/']
 
 This document describes how to deploy a TiDB cluster on Alibaba Cloud Kubernetes with your laptop (Linux or macOS) for development or testing.
 
+To deploy TiDB Operator and the TiDB cluster in a self-managed Kubernetes environment, refer to [Deploy TiDB Operator](deploy-tidb-operator.md) and [Deploy TiDB in General Kubernetes](deploy-on-general-kubernetes.md).
+
 ## Prerequisites
 
 - [aliyun-cli](https://github.com/aliyun/aliyun-cli) >= 3.0.15 and [configure aliyun-cli](https://www.alibabacloud.com/help/doc-detail/90766.htm?spm=a2c63.l28256.a3.4.7b52a893EFVglq)

en/deploy-on-aws-eks.md

@@ -8,6 +8,8 @@ aliases: ['/docs/tidb-in-kubernetes/dev/deploy-on-aws-eks/']
 
 This document describes how to deploy a TiDB cluster on AWS Elastic Kubernetes Service (EKS).
 
+To deploy TiDB Operator and the TiDB cluster in a self-managed Kubernetes environment, refer to [Deploy TiDB Operator](deploy-tidb-operator.md) and [Deploy TiDB in General Kubernetes](deploy-on-general-kubernetes.md).
+
 ## Prerequisites
 
 Before deploying a TiDB cluster on AWS EKS, make sure the following requirements are satisfied:

en/deploy-on-gcp-gke.md

@@ -11,6 +11,8 @@ aliases: ['/docs/tidb-in-kubernetes/dev/deploy-on-gcp-gke/']
 
 This document describes how to deploy a GCP Google Kubernetes Engine (GKE) cluster and deploy a TiDB cluster on GCP GKE.
 
+To deploy TiDB Operator and the TiDB cluster in a self-managed Kubernetes environment, refer to [Deploy TiDB Operator](deploy-tidb-operator.md) and [Deploy TiDB in General Kubernetes](deploy-on-general-kubernetes.md).
+
 ## Prerequisites
 
 Before deploying a TiDB cluster on GCP GKE, make sure the following requirements are satisfied:

en/deploy-tidb-operator.md

@@ -22,6 +22,12 @@ Before deploying TiDB Operator, make sure the following items are installed on y
 
 TiDB Operator runs in the Kubernetes cluster. You can refer to [the document of how to set up Kubernetes](https://kubernetes.io/docs/setup/) to set up a Kubernetes cluster. Make sure that the Kubernetes version is v1.12 or higher. If you want to deploy a very simple Kubernetes cluster for testing purposes, consult the [Get Started](get-started.md) document.
 
+For some public cloud environments, refer to the following documents:
+
+- [Deploy on AWS EKS](deploy-on-aws-eks.md)
+- [Deploy on GCP GKE](deploy-on-gcp-gke.md)
+- [Deploy on Alibaba Cloud ACK](deploy-on-alibaba-cloud.md)
+
 TiDB Operator uses [Persistent Volumes](https://kubernetes.io/docs/concepts/storage/persistent-volumes/) to persist the data of TiDB cluster (including the database, monitoring data, and backup data), so the Kubernetes cluster must provide at least one kind of persistent volumes. For better performance, it is recommended to use local SSD disks as the volumes. Follow [this step](#configure-local-persistent-volumes) to provision local persistent volumes.
 
 It is recommended to enable [RBAC](https://kubernetes.io/docs/admin/authorization/rbac) in the Kubernetes cluster.