title: vscode "Go to symbol in workspace" works only with open files on typescript project
body: <p>I am trying to use the &quot;Go to symbol&quot; feature in vscode in my typescript project but it doesn't seem to work like I would expect.</p>
  <p>These are the actions I do:</p>
  <ul>
  <li>Open my project (single directory project) with vscode</li>
  <li>Assure that no file is open</li>
  <li>Press cmd+t (or cmd+p and then type # to start the symbol search)</li>
  <li>Type the name of a function declared somewhere in my workspace (like renderHtmlMiddleware)</li>
  </ul>
  <h1>What I would expect:</h1>
  <p>VSCode finds a match and allows me to open the file to the line of the declaration</p>
  <h1>What actually happens:</h1>
  <p>VSCode doesn't find any match</p>
  <h1>Additional details</h1>
  <p>Only if I open the file the search actually works.
  It appears that the search is working only on open files, but I would like it to work on my workspace.</p>
  <p>Before you suggest to create a tsconfig.json file, I already have one, but it doesn't seem to fix the issue.</p>