Datatable: adding the option to add a <caption>

[Lb-lea]

Hello,
Table captions and summaries provide information to give the user a quick information of the table content. While they are not required to meet WCAG 2.0, they can still be very useful for screen reader users.
Usage example

<table>
  <caption>Explaining what this table is about</caption>
  <tr>...</tr>
</table>

or

<table   summary="Explaining what this table is about">

It might be interesting to add those or one of those optional field in the datatable.