When I started my solution in VS Community 2019 it said that the Xamarin Forms Shell did not support UWP. I just upgraded VS to 16.9.2 and it now says UWP is a "Preview feature."
So I have a partially-completed Solution with Android and iOS projects. How do I add a UWP project to the existing mostly-completed solution? I try Solution->Add->Project and it seems to want to start a whole new app.