(fix) generated xml documentation would be included into nuget package

[fshchudlo]

No description provided.

[fshchudlo]

Hi!
As I can see build is failed because of tests execution is too long. Can we do anything with that?

[baronfel]

I think the correct way to do this is to add the line <GenerateDocumentationFile>true</GenerateDocumentationFile> to the project file instead of the manual copying you have here.

[fshchudlo]

Actually not.
GenerateDocumentationFile option doesn't work well. Also my change is what Visual Studio generated when I've check "Generate XML documentation file" checkbox, not the manual change.