Add cloud starter workflows
Add language categories matching linguist identifiers so that .NET Core template is recommended.
The .NET Core template is not ASP specific. Change the name to ".NET Core".
It was pointed out (https://github.com/actions/labeler/issues/18) that when using the labeler from the starter-workflow, it's not clear that there is more work to do to configure the action. Add information and link to the action's README.