Add man pages for hackrf utilities

[postmodern]

Having man pages for the hackrf utilities would be an improvement over the --help output. I highly suggest using one of the many utilities that can convert Markdown into Roff, and then commit the resulting Roff files.

┆Issue is synchronized with this Basecamp todo by Unito

[dominicgs]

It appears that man pages are added to the Debian package, as shown here: http://manned.org/hackrf_info/3bb42866

Perhaps we could speak to the package maintainer and bring those man pages upstream.