Support for multiple csproj files (for projects with multiple csproj's)

[ghost]

For instance in Unity projects there's two csproj files:
Assembly-CSharp-Editor.csproj and Assembly-CSharp.csproj
While some of the files should be added toAssembly-CSharp.csproj, others should be added to Assembly-CSharp-Editor.csproj.

Prompting to add file to one csproj, while ignoring another would be nice.
Supplying multiple options in the file drop-down menu would also be nice.

[vladipus]

+1
good extension!

[VergilGao]

i think if it worked, i would turn to vscode at once!