Frontend: Markdown parsing: added "br"

added the rendering for the `<br/>` tag that gets added when a line end
with two spaces

src/ui/src/components/SlideItem.js

@@ -78,6 +78,8 @@ const SlideItem = ({item}) => {
 				return <i><Children items={item.tokens} /></i>
 			case "html":
 				return <span dangerouslySetInnerHTML={{__html : item.raw}}></span>
+			case "br":
+				return <br />;
 			case "link":
 			case "text":
 				return <>{item.tokens ? <Children items={item.tokens} /> : processEscapeSequences(item.text)}</>