How to add dependency to exists visuald project?

[Dmitry via Digitalmars-d-ide]

Hi. I'm trying do my next project using D. Previously I used 
Xamarin Studio, but for serious work I need a debugger. So, I try 
Visual Studio + VisualD.

I create a new project:

     dub init projectname

Add a dependency to dub.sdl, then generate solution for Visual 
Studio:

     dub generate visuald

Open it in Visual Studio and do some changes (create new folders, 
new modules, etc).
Then I need add new dependency. I edit dub.sdl, but what then? If 
I generate project again

     dub generate visuald

then I'll lose all changes which I did (new folders, new modules, 
etc).

How I can add new dependency and continue work?