Included man page in install step

Man pages were not being distributed or installed by default. Included
that info in order to port to FreeBSD.
Added packaging/ subdir

The packaging subdir is for retaining copies of files used in
distribution to specific platforms and package managers. For now, I've
taken the convention of <os name>-<package manager>.
Added instructions on how to brew pk

Given that pk can't be brewed directly, I put instructions in the
comments in the top of the brew formula.