onboarding AZ_DESKTOPVIRTUALIZATION (Azure#1741)

* generate and run

* fix style issues

* live test

* fix issues

* run test

* add readme

* add checkers in test override

* flake8 on manual

.github/CODEOWNERS

@@ -133,3 +133,5 @@
 /src/blockchain/ @MyronFanQiu
 
 /src/codespaces/ @derekbekoe
+
+/src/desktopvirtualization/ @changlong-liu

src/desktopvirtualization/HISTORY.rst

@@ -0,0 +1,8 @@
+.. :changelog:
+
+Release History
+===============
+
+0.1.0
+++++++
+* Initial release.

src/desktopvirtualization/README.md

@@ -0,0 +1,59 @@
+# Azure CLI Desktop Virtualization Extension #
+This is a extension for desktop virtualization features.
+
+### How to use ###
+Install this extension using the below CLI command
+```
+az extension add --name desktopvirtualization
+```
+
+### Included Features
+The desktop virtualization is a desktop and app virtualization service that runs on the cloud. [more info](https://docs.microsoft.com/en-us/azure/virtual-desktop/overview)
+#### Host Pool:
+Host pools are a collection of one or more identical virtual machines (VMs) within Windows Virtual Desktop environments: [more info](https://docs.microsoft.com/en-us/azure/virtual-desktop/create-host-pools-azure-marketplace)\
+*Examples:*
+```
+az desktopvirtualization hostpool create \
+    --location "centralus" \
+    --description "des1" \
+    --friendly-name "friendly" \
+    --host-pool-type "Pooled" \
+    --load-balancer-type "BreadthFirst" \
+    --max-session-limit 999999 \
+    --personal-desktop-assignment-type "Automatic" \
+    --registration-info expiration-time="2020-10-01T14:01:54.9571247Z" registration-token-operation="Update" \
+    --sso-context "KeyVaultPath" \
+    --tags tag1="value1" tag2="value2" \
+    --name "MyHostPool" \
+    --resource-group "MyResourceGroup"
+```
+
+#### Application Group:
+Each host pool can contain an application group that users can interact with as they would on a physical desktop: [more info](https://docs.microsoft.com/en-us/azure/virtual-desktop/manage-app-groups)\
+*Examples:*
+```
+az desktopvirtualization applicationgroup create \
+    --location "centralus" \
+    --description "des1" \
+    --application-group-type "RemoteApp" \
+    --friendly-name "friendly" \
+    --host-pool-arm-path "/subscriptions/daefabc0-95b4-48b3-b645-8a753a63c4fa/resourceGroups/MyResourceGroup/providers/Microsoft.DesktopVirtualization/hostPools/MyHostPool" \
+    --tags tag1="value1" tag2="value2" \
+    --name "MyApplicationGroup" \
+    --resource-group "MyResourceGroup"
+```
+
+#### Workspace:
+An application group can be registered to a workspace: [more info](https://docs.microsoft.com/en-us/azure/virtual-desktop/create-validation-host-pool)\
+*Examples:*
+```
+az desktopvirtualization workspace create \
+    --resource-group "MyResourceGroup" \
+    --location "centralus" \
+    --description "des1" \
+    --friendly-name "friendly" \
+    --tags tag1="value1" tag2="value2" \
+    --name "MyWorkspace"
+```
+
+If you have issues, please give feedback by opening an issue at https://github.com/Azure/azure-cli-extensions/issues.