tin-summer does not count the size of directories

[sharkdp]

How to reproduce:

Run this in an empty directory:

for i in {1..1000}; do mkdir $i; done
echo -n "test" > 123/file

If we now use du to report the "disk usage" and the "apparent size" of that directory, we get:

▶ du -s -B1
4096	.

▶ du -s -B1 --apparent-size
60064	.

However, sn only reports the 4 bytes from the 123/file:

▶ sn files -d0
4    b	 .

▶ sn parallel -d0
4    b	 .