title: vscode does not jump to definition
body: <p>I have a node project that uses ws. VSCode knows about the websocket events and functions but if I add something to prototype then it is recognized in suggestions but I can't jump to definition. It say: <strong><em>No definition found for 'setDefaults'</em></strong>. Is there something I need to configure in VScode to work or am I using it wrong?</p>
  
  <p><a href="https://i.stack.imgur.com/SqmlD.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SqmlD.png" alt="enter image description here"></a></p>
  
  <p>The source to easy copy:</p>
  
  <pre><code>const WebSocket = require('ws');
  
  WebSocket.prototype.setDefaults = function()
  {
      console.log("defaults")
  }
  
  
  ws = new WebSocket();
  
  ws.setDefaults()
  </code></pre>
  
  <p>I also tried Find all references, but it does not find the usage of the method.</p>