Override Column Headers

Full Code

<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <title>ZingGrid: Simple Grid</title>
  <script nonce="undefined" src="https://cdn.zinggrid.com/zinggrid.min.js"></script>
  <style>
    body {
      background: #e6e6e6;
    }

    zing-grid[loading] {
      height: 373px;
    }
  </style>
</head>

<body>
  <zing-grid caption="EPL Top Scorers" layout="row" layout-controls="disabled" viewport-stop>
    <zg-data data='[
        {
          "playerName": "Eden Hazard",
          "playerClub": "Chelsea",
          "goalsScored": 5          
        },
        {
          "playerName": "Aleksandar Mitrovic",
          "playerClub": "Fulham",
          "goalsScored": 5   
        },
        {
          "playerName": "Sergio Agüero",
          "playerClub": "Manchester City",
          "goalsScored": 4   
        },
        {
          "playerName": "Romelu Lukaku",
          "playerClub": "Manchester United",
          "goalsScored": 4   
        },
        {
          "playerName": "Sadio Mané",
          "playerClub": "Liverpool",
          "goalsScored": 4   
        }
      ]'></zg-data>
    <zg-colgroup>
      <zg-column index="playerName" header="Player"></zg-column>
      <zg-column index="playerClub" header="Club"></zg-column>
      <zg-column index="goalsScored" header="Goals"></zg-column>
    </zg-colgroup>
  </zing-grid>
  <script>
    ZingGrid.setLicense(['26ccbfec16b8be9ee98c7d57bee6e498']);
  </script>
</body>

</html>