It must be really obvious and I'm just an idiot.
I need to add a Xamarin Component (no nuget package available) to my Xamarin Forms app (iOS, Android, WP). iOS and Android have a 'components' folder under the project which I can right click on and get options to add components from the Xamarin Component Store. Windows Phone does not have this special folder, and I cannot find an Add Component option on any of the context menus in solution explorer. The package in question shows it supports WP on it's home page in the Xamarin Store, so I assume this is possible.
What is the correct way to add a Xamarin Component into a Windows Phone app (for a Xamarin Forms solution)?