When no margin detected, reserve a bit more space for comments

copienator/commands/annotating_by_label.py

@@ -87,6 +87,7 @@ def save_batch(batch, prefix, group_id, output_root: Path) -> None:
                 "id": student_id,
                 "label": label,
                 "header_height": header_height,
+                "layout": image.info.get('annotation_layout', annotating.layout_for(None)),
                 "hmin": current_y,
                 "hmax": current_y + image.height,
             }