Add CSI Windows Suppoort Doc

add doc for csi windows support

Author: jingxu97

README.md

@@ -64,6 +64,10 @@ This driver supports only one topology key:
 `topology.gke.io/zone`
 that represents availability by zone (e.g. `us-central1-c`, etc.).
 
+### CSI Windows Support
+
+GCE PD driver starts to support CSI Windows (alpha) with version v1.0.*. It requires to install [CSI Proxy] (https://github.com/kubernetes-csi/csi-proxy) binary on each Windows node. The latest version of CSI Proxy is Beta. GCE PD driver start to support Beta CSI Proxy starting from v1.1.0. Starting Kubernetes 1.19, CSI Proxy binary is automatically installed during node start up. In Kubernetes 1.20, CSI Proxy will be running a windows service to improve its stablibity.
+
 ### Features in Development
 
 | Feature         | Stage | Min Kubernetes Master Version | Min Kubernetes Nodes Version | Min Driver Version | Deployment Overlay |

docs/kubernetes/user-guides/windows.md

@@ -0,0 +1,27 @@
+# Kubernetes CSI Windowos User Guide
+
+>**Attention:** CSI Windows Beta is only available in the driver version v1.1.0+
+>**Attention:** CSI Windows Alpha is only available in the driver version v1.0.0-v1.0.*
+
+### Install CSI Proxy binary
+CSI proxy can be installed as binary or run as a Windows service on each Windows node. Starting Kubernetes 1.19, [CSI Proxy Alpha](https://github.com/kubernetes-csi/csi-proxy/releases/tag/v0.1.0) binary is automatically installed during node start up. In Kubernetes 1.20, [CSI Proxy Beta.1 v0.2.1](https://github.com/kubernetes-csi/csi-proxy/releases/tag/v0.2.1) is installed and running as a windows service to improve its stablibity.
+
+
+### Install Driver with CSI Windows support
+
+1. [One-time per project] Create GCP service account for the CSI driver and set required roles
+
+```
+$ PROJECT=your-project-here                       # GCP project
+$ GCE_PD_SA_NAME=my-gce-pd-csi-sa                 # Name of the service account to create
+$ GCE_PD_SA_DIR=/my/safe/credentials/directory    # Directory to save the service account key
+$ ./deploy/setup-project.sh
+```
+
+2. Deploy driver to Kubernetes Cluster
+
+```
+$ GCE_PD_SA_DIR=/my/safe/credentials/directory    # Directory to get the service account key
+$ GCE_PD_DRIVER_VERSION=alpha                     # Currently alpha deploy Driver version with Windows Alpha support. Will add beta supporot to beta GCE_PD_DRIVER_VERSION deployment script.
+$ ./deploy/kubernetes/deploy-driver.sh
+```