Add option to export_to_markdown to mark page breaks

[cau-git]

As suggested in this discussion, we should add a placeholder feature for page breaks, the same way we support placeholders for pictures.

• The placeholder text for page breaks should by default contain the page number.
• It should be disabled as a default.

[chakravarthik27]

Hi @cau-git

I am interested in working on this issue.

[cau-git]

@chakravarthik27 Thanks, we would welcome that you make a contribution for this issue!

As a starting point, it would require extension of this method.

[sunwoongc]

@chakravarthik27
Hi, I'm also very interested in resolving this issue. I've found a solution that works in my case, though I'm not sure if it’s a general fix. Would you mind if I also worked on this?