Better front image positioning for PDF export (editorial)

This is to propose a way to make PDFs display (cover) images on page 1 of export.

There are scenarios where circumstances (like long property sections) result in PDFs being exported w/ images not shown on front page of PDF. This seems even true for settings where there is a "cover image" present.

Reasoning: there are many situation – which I would call "editorial" – where it´s helpful/expected to have an image on the front page of content PDFs. The logic is pretty much the same as for the cards in the dashboard view.

It does not only look better, but it is often helpful to needed for browsing situations, e.g. where I review different PDFs in a stack, want to quickly skim PDFs in different apps etc. Also – and making this more pivotal – thumbnails are mostly created from page 1 of any given PDF, so the effect even promulgates into very different sets and contexts of ones digital ecosystem. For this it is especially true to think of "a picture is worth 1000 words…