showdownjs/test/features/tables/#256.table-header-separators-should-not-require-3-dashes.html

<table>
    <thead>
    <tr>
        <th>key</th>
        <th>value</th>
    </tr>
    </thead>
    <tbody>
    <tr>
        <td>My Key</td>
        <td>My Value</td>
    </tr>
    </tbody>
</table>