title: Warning: .NETStandard.2.0.0.0 Library cannot be imported again
body: <p>I'm getting this annoying warning message. </p>
  
  <p>"{your path}\packages\NETStandard.Library.2.0.0\build\NETStandard.Library.targets" cannot be imported again. It was already imported at "{your project path}". This is most likely a build authoring error. This subsequent import will be ignored. Data...(See my own answer below)</p>