Add an article about using FreeBSD on laptops. This document aims to
be a quick HOWTO for the various issues likely to be interesting for
laptop users; such as power management, winmodems, XFree86 on laptop
hardware, etc..

This is just a start, and there is plenty of room for improvement.

PR: docs/30199
Submitted by: Rahul Siddharthan <rsidd@physics.iisc.ernet.in>
Reviewed by: dd