Fix sizes of results

I accidentally used binary prefixes instead of decadic :-/

README

@@ -27,8 +27,8 @@ auxiliary storage fit in RAM, it should be similarly fast (the
 `cache.no-flush=yes` option does not flush the host's block cache, or
 something, I might not understand this correctly but I think it goes brrrrr).
 
-After about 1.5 h we get the result: 5.6 GB worth of images – 2.8 GB for the
-iso, 2.8 for netboot files (which seem to mainly duplicate the iso contents,
+After about 1.5 h we get the result: 6 GB worth of images – 3 GB for the
+iso, 3 for netboot files (which seem to mainly duplicate the iso contents,
 but I understand why they were exported separately).
 
 In hindsight: I could also tweak the `pacman.conf`, but I came up with the