title: Make expandable table rows accessible
body: <p>I am creating a React component for tables with expandable rows, and I want to make it as accessible as possible.</p>
  
  <p>Here's a simple, unstyled example of what I'm making:</p>
  
  <p><a href="https://codesandbox.io/s/nz8r2w74j" rel="nofollow noreferrer">https://codesandbox.io/s/nz8r2w74j</a></p>
  
  <p>Whenever I click the "more info" button, a new row is added, with info about the row in front of it. </p>
  
  <p>What do I need to add in terms of wai-aria roles, focus management and other stuff in order to make it truly accessible?</p>