Windows: add libzip dll to installer package

This was missing in the first set of Subsurface 3.0 binaries

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Documentation: correct mis-spelling

It's the Heinrichs Weikamp Frog, not From.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>