Add total dirsize to `lsd -l`

Generally when you use `ls -l`, the first line of the list is the known size of all the files in the directory. This is just tiny enhancement for people who expect to know the total dir size. Its likely its just a forgotten feature.

The issue names the lsd -l command but no files or tests. Start by locating the long-listing output and how directory entries are measured, then compare lsd -l with ls -l. Done means the listing includes the total directory size in the first line.

Written by the indexing model from the issue text.