title: Define only object's key and auto generate value's type
body: <p>I'm looking trying to do something like:</p>
  <pre><code>type Sizes = 'small' | 'large';
  
  const CONFIG_BY_SIZE: Record&lt;Sizes, any&gt; = {
      small: {
          a: ...,
          b: ...,
          c: ...,
      },
      large: {
          a: ...,
          b: ...,
          c: ...,
      },
  }
  </code></pre>
  <p>it works, but when i try to type <code>CONFIG_BY_SIZE.large.</code> there is no auto complete for <code>a</code> or <code>b</code> or <code>c</code>. I think it is because i define the value as any.
  the values itself are quite large, so i prefer it to be auto generated if possible.</p>
  <p>my goals is to define the key as <code>Sizes</code> but i still can have autocomplete for the value.
  how do i achieve this?</p>
  <p>Thanks!</p>