showdownjs/test/features/tables/basic-alignment.html

<table>
  <thead>
    <tr>
      <th style="text-align:left;">First Header</th>
      <th style="text-align:left;">Second Header</th>
    </tr>
  </thead>

  <tbody>
    <tr>
      <td style="text-align:left;">Row 1 Cell 1</td>
      <td style="text-align:left;">Row 1 Cell 2</td>
    </tr>

    <tr>
      <td style="text-align:left;">Row 2 Cell 1</td>
      <td style="text-align:left;">Row 2 Cell 2</td>
    </tr>

  </tbody>
</table>