title: Visual studio project.json does not have a runtime section
body: <p>I ran into a error in visual studio 2017, I'm searching over the net but I don't find anything usefull, so my question is, how can I solve this:</p>
  
  <blockquote>
    <p>Severity  Code    Description Project File    Line    Suppression State
    Error       Your project.json doesn't have a runtimes section. You should add '"runtimes": { "win": { } }' to your project.json and then re-run NuGet restore.</p>
  </blockquote>
  
  <p>I was seaching for file where is located in my project but with no succsess.</p>
  
  <p>Thanks          </p>