Include source code for library in that library

I've a plugin based web app that allows an administrator to assign various small pieces of functionality (the actual functionality is unimportant here) to users. This functionality is configurable and an administrator having an understanding of the plugins is important. The administrator is technical enough to be able to read the very simple source code for these plugins. (Mostly just arithmetic).

I'm aware there are a couple of questions already about accessing source code from within a DLL built from that source:

How to include source code in dll? for example.

I've played with getting the .cs files into a /Resources folder. However doing this with a pre-build event obviously don't include these files in the project. So VS never copies them and I'm unable to access them on the Resources object.

Is there a way to reference the source for a particular class... from the same assembly that I'm missing? Or alternatively a way to extract COMPLETE source from the pdb for that assembly?

As I've access to the source code, I don't want to go about decompiling it to display it. This seems wasteful and overly complicated.