Whiteboard for drawing on top of slides

[sbibauw]

First, congrats on Marp! It's simply the most efficient slides creator I've used and it really saves me huge amounts of time.

Something that would make a great addition to Marp is the ability to draw on top of the slides, for annotation, drawing or quick live additions. As I use Marp in online lectures, it's quite easy for me to use a drawing tablet to annotate. Right now, I do it with the Zoom annotation feature, but it would be much more fluid to do it in the browser.

I've discovered @Juanvvc 's templates which offer great ideas, and he has added a simple whiteboard JS to the slides allowing to do precisely that.

I think this is such a useful tool that it could be integrated into Marp in some way, at least with an officially recommended/maintained JS + documentation of the feature in the main Marp docs.