Suggestion: Add functionality to create a "full" solution

[henrikrxn]

I looked at the documentation for dotnet new and there does not seem to be an option that let's you add a solution file along the project file

So I guess there are, at least, these options:

• Always add the .sln file, which I personally do not like
• Another template carter-full-solution (or whatever you want to call it) that created a fresh solution
• Have the current template always add the .sln file and add a new template carter-add-project (or whatever you want to call it) that just adds a project. This would be for the "I would like to experiment with Carter within an existing solution" scenario