Support Lazy Loading with data-src for <embed> element ?

[cderv]

Hi,

I noticed digging through some issues (jgm/pandoc#7830) that setting <embed data-src=> does not work in revealjs. Currently Pandoc sets this attributes and the resulting presentation does not load the embed file.

It seems like it is not among the supported element

reveal.js/js/controllers/slidecontent.js

Lines 52 to 59 in f7c5964

	// Media elements with data-src attributes
	queryAll( slide, 'img[data-src], video[data-src], audio[data-src], iframe[data-src]' ).forEach( element => {
	if( element.tagName !== 'IFRAME' || this.shouldPreload( element ) ) {
	element.setAttribute( 'src', element.getAttribute( 'data-src' ) );
	element.setAttribute( 'data-lazy-loaded', '' );
	element.removeAttribute( 'data-src' );
	}
	} );

Does it make sense to add support in there for lazy loading also using HTML5 <embed> ?