Documentation: fixed a few typos

- Suunto Viper is actually Vyper.
  I actually used to own both a Vyper and a Vyper Air, so I care. :-)
- Fixed a few other small typos.

Signed-off-by: Reinout Hoornweg <reinout@xs4all.nl>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>