Thank you for contacting us.
We have not yet updated our documentation with getting started instructions for Windows 8.1 projects. The Windows Phone information is related to Windows Phone 8 Silverlight
projects. We will soon update the information and we apologize for any inconvenience caused.
Here are the references that you have to add to your Windows Phone 8.1 project:
I have also attached a sample.
As for UWP, we will provide support shortly after Xamarin supports it officially, most likely between Q2 and Q3 this year.
I hope this helps. Please, let us know if you have any other issues.
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Feedback Portal
and vote to affect the priority of the items