mod: use 3mm for 5cm in rib instead of 8cm

Disappointed about the pattern. It’s too simple and not written in details. It’s only good for experienced knitters, not me. If I’d have known this sweater is from bottom up, I wouldn’t purchase it.

Since it’s a bottom up that I couldn’t measure it on my body, the length is longer than I expect. But overall, it’s a beautiful sweater and I like it!