Update Azure config

- Add Ubuntu 20.04 to OS options, and set as default

azure/README-zh.md

@@ -9,7 +9,7 @@
  - Username for VPN **and** SSH （用户名）
  - Password for VPN **and** SSH （密码）
  - IPsec Pre-Shared Key for VPN （IPsec 预共享密钥）
- - Operating System Image （操作系统镜像，Debian 9 或 Ubuntu 18.04/16.04 LTS）
+ - Operating System Image （操作系统镜像，Ubuntu 20.04/18.04/16.04 或 Debian 9）
  - Virtual Machine Size （虚拟机大小，默认值： Standard_B1s）
 
 **注：** \*不要\* 在值中使用这些字符： `\ " '`
@@ -20,7 +20,7 @@
     <img src="../docs/images/azure-deploy-button.png" alt="Deploy to Azure" />
 </a><br><br>
 
-在完成部署之后，Azure 会有提示。下一步： [配置 VPN 客户端](../docs/clients-zh.md)。
+在完成部署之后，Azure 会有提示。下一步：[配置 VPN 客户端](../README-zh.md#下一步)。
 
 ## 作者
 

azure/README.md

@@ -9,7 +9,7 @@ Customizable with the following options:
  - Username for VPN **and** SSH
  - Password for VPN **and** SSH
  - IPsec Pre-Shared Key for VPN
- - Operating System Image (Debian 9 or Ubuntu 18.04/16.04 LTS)
+ - Operating System Image (Ubuntu 20.04/18.04/16.04 or Debian 9)
  - Virtual Machine Size (Default: Standard_B1s)
 
 **Note:** DO NOT use these special characters within values: `\ " '`
@@ -20,7 +20,7 @@ Press this button to start:
     <img src="../docs/images/azure-deploy-button.png" alt="Deploy to Azure" />
 </a><br><br>
 
-When the deployment finishes, Azure displays a notification. Next steps: [Configure VPN Clients](../docs/clients.md).
+When the deployment finishes, Azure displays a notification. Next steps: [Configure VPN Clients](../README.md#next-steps).
 
 ## Authors
 

azure/azuredeploy.json

@@ -24,13 +24,14 @@
     "image": {
       "type": "string",
       "allowedValues": [
-        "ubuntu1804",
+        "ubuntu20.04",
-        "ubuntu1604",
+        "ubuntu18.04",
+        "ubuntu16.04",
         "debian9"
       ],
-      "defaultValue": "debian9",
+      "defaultValue": "ubuntu20.04",
       "metadata": {
-        "description": "OS to use. Debian 9 or Ubuntu 18.04/16.04 LTS"
+        "description": "OS to use. Ubuntu 20.04/18.04/16.04 or Debian 9."
       }
     },
     "VMSize": {
@@ -61,13 +62,19 @@
     "vhdStorageType": "Standard_LRS",
     "vnetId": "[resourceId('Microsoft.Network/virtualNetworks', variables('virtualNetworkName'))]",
     "SubnetRef": "[concat(variables('vnetId'), '/subnets/', variables('subnetName'))]",
-    "ubuntu1804": {
+    "ubuntu20.04": {
+      "publisher": "Canonical",
+      "offer": "0001-com-ubuntu-server-focal",
+      "sku": "20_04-lts",
+      "version": "latest"
+    },
+    "ubuntu18.04": {
       "publisher": "Canonical",
       "offer": "UbuntuServer",
       "sku": "18.04-LTS",
       "version": "latest"
     },
-    "ubuntu1604": {
+    "ubuntu16.04": {
       "publisher": "Canonical",
       "offer": "UbuntuServer",
       "sku": "16.04-LTS",