title: VS Code: how to keep two projects open in tabs (instead of two windows)?
body: <p>I have VS Code 1.15.1 and when I work at two projects at once, I choose File -> New Window and open the second project. Clicking File -> New Window opens new window with VS Code. 
  On my other computer (not sure about the VS Code version there), when I click File -> New Window, instead of opening new window, it will rather open new tab, so that I end up with two tabs in one window, each tab for one project and the active tab occupies whole screen estate.</p>
  
  <p>Any ideas what should I change in Settings to achieve this "single window, multiple tabs" layout when having multiple projects?</p>
  
  <p>I use macos (not sure if OS may be somehow related to the window management settings)</p>