Add ResourceDictionary to class library

Question

I created a class library which is contained of WPF Windows and some user controls inherited from my c# classes that helps me to customize certain wpf controls.

Now

Answer 1

@punker76's answer is great and helped me a lot, but it's worth adding that if you create an empty file and add a resource tag into it you should also go to file properties, set BuildAction to Resource, Copy To... to Do not copy and clear CustomTool property if it's set.