Attach .fx file to class lib, publish to nuget and load in game

How can I attach a .fx file or a .png to a class lib and then how can I load it in the projects using this lib.

I found an article on the microsoft xna pages but I dont understand it… :frowning:
Maybe someone here has done it and can tell me how to do it

Are you publishing the lib as a nuget package, or pulling it in as a git submodule or something?