Can we have nested bookmarks, working like a filesystem:
% Bookmark
- --------
dir-1
dir-2
...
mark-n ~/work/file-n.txt
When I open dir-1 I have another screen with bookmarks, located in this dir:
% Bookmark
- --------
dir-1-1 ~/work/file-1.txt
dir-1-2 ~/work/file-2.txt
mark-1 ~/work/file-n.txt
So, we upgrade the bookmarks data structure from a list to a tree.