Add solution items to multiproject template

Hi,

I'm trying to create a multiproject template which includes solution items.

So far, I've been able to create the template. When the user creates a new project using this template, it creates a solution containing three projects.

However I didn't manage to modify the template to add solution items to the solution.

Those files are content (not projects) and are used to enable nuget package restore.

Any help would be welcome;

Régis Portalez