title: Showing a sub-table under Material-table detail panel
body: <p>I am trying to add <a href="https://material-ui.com/components/tables/#dense-table" rel="nofollow noreferrer">dense table</a> under <a href="https://material-table.com/#/docs/features/detail-panel" rel="nofollow noreferrer">material-table detail panel</a> but couldn't managed to do it.</p>
  
  <p>I want to show <strong>id</strong>, <strong>project_name</strong> and <strong>links</strong> on the main table and when you click the project rows it should show that projects <strong>features</strong> array as a sub-table.</p>
  
  <p>Here what I tried to do but it currently it shows every feature on every row.
  Thanks in advance.</p>
  
  <p><a href="https://repl.it/@CagatayCanK/Create-React-App" rel="nofollow noreferrer">https://repl.it/@CagatayCanK/Create-React-App</a></p>