markdown: Add support for HTML table column align attribute

[RemcoSmitsDev]

This PR allows you to define align="right" for example to change the default alignment on HTML table columns. This PR also refactors where we store the alignments in order to make it so you can define it column based instead of only row based.

See that the Revenue column is left aligned instead of the default centered.

Result

Code example

<table>
    <tr>
        <th rowspan="2">Region</th>
        <th colspan="2" align="left">Revenue</th>
        <th rowspan="2">Growth</th>
    </tr>
    <tr>
        <th>Q2 2024</th>
        <th>Q3 2024</th>
    </tr>
    <tr>
        <td>North America</td>
        <td>$2.8M</td>
        <td>$2.4B</td>
        <td>+85,614%</td>
    </tr>
    <tr>
        <td>Europe</td>
        <td>$1.2M</td>
        <td>$1.9B</td>
        <td>+158,233%</td>
    </tr>
    <tr>
        <td>Asia-Pacific</td>
        <td>$0.5M</td>
        <td>$1.4B</td>
        <td>+279,900%</td>
    </tr>
</table>

Release Notes:

• markdown preview: Add support for HTML table column align attribute

[bennetbo]

Thank you!