title: Unity type or namespace name 'InputSystem' does not exist in the namespace 'UnityEngine'
body: <p>I have installed the new InputSystem package in my Unity project. I have set the input to &quot;new inputsystem&quot; in the Unity Player Settings.
  I have quit and restarted both Unity and VS Code.</p>
  <p>But when I try to use the system in VS Code, I immediately get this error:</p>
  <pre><code>using UnityEngine;
  using System.Collections;
  using UnityEngine.InputSystem;              // &lt;-error
  using UnityEngine.InputSystem.Controls;     // &lt;-error
  </code></pre>
  <blockquote>
  <p>The type or namespace name 'InputSystem' does not exist in the namespace 'UnityEngine' (are you missing an assembly reference?) [Assembly-CSharp]</p>
  </blockquote>
  <p>What can I do to make VS Code recognise the Unity InputSystem package?</p>