Feature: render small preview on the devcards overview page

Would be nice to have a small preview of the devcard on the overview (navigation) page. Not sure how that would have to look with multiple defcards.

Use-case: we are documenting all our reusable components, using devcards. For new developers in our company it would be useful to have a visual clue, so they don't have to navigate through all the components.

Start at the devcards overview or navigation page and trace how multiple devcards are listed and rendered. Decide how a small visual preview should behave when several devcards are present, then verify the overview gives new developers a useful visual clue without requiring navigation into each component.

Written by the indexing model from the issue text.