Add data attribute to html tag via xml

I'm working on a template and I need to add some styling via xml.

I know I can use:

htmlTag="div" to give the content a div tag

and I know I can use:

htmlClass="my-class" to give the content some styling

but I also need to insert some custom text: data-grid-margin

so the output would be something like this:

<div class="my-class" data-grid-margin>This is my content</div>

Is there a way I can get the data-grid-margin insert via an xml file?

T.i.a.