title: Type Definitions for sub components
body: <p>I have defined sub-components to my styled component, and am trying to provide type definitions for it - TSC complains 'Property 'PrimaryText' does not exist on type 'StyledComponentClass'. Similarly for 'SubText'. </p>
  
  <pre><code>export const Tab = styled(NavLink)`
      border: 1px solid rgba(0, 119, 204, 0.5);
      box-shadow: 0 0 8px 0 rgba(0, 0, 0, 0.08), 0 2px 15px 0 rgba(0, 0, 0, 0.08);
      box-sizing: border-box;
      height: 60px;
      min-width: 125px;
      padding: 10px 15px;
      cursor: pointer;
  `;
  
  Tab.PrimaryText = styled(Box)`
      height: 22px;
      color: #3d464d;
      font-size: 16px;
      font-weight: 600;
      line-height: 22px;
  `;
  
  Tab.SubText = styled(Box)`
      height: 15px;
      color: #525d66;
      font-size: 11px;
      line-height: 15px;
  `;
  </code></pre>
  
  <p>How do I go about specifying the types? Looked around a lot. There's hardly any reference.</p>