Add doc tags to publishto-computeengine.ps1
Add doc tags to publishto-computeengine.ps1

Change-Id: I2a3b9404332fc46399964aad039d5cf8bd67cc0f

GoogleCloudPlatform/getting-started-dotnet,GoogleCloudPlatform/getting-started-dotnet,GoogleCloudPlatform/getting-started-dotnet