I'm a bit confused here. So it looks like when finding first list items, changing the indent level (ilvl) would cause a list item to be marked as the first. So two list items with the same num_id, but different ilvls might both be marked as `is_first_list_item`.

With `is_last_list_item`, why don't we care about the indentation level? It seems like this will result in us not necessarily having a matching last item for each first item, right?