Improve manpage and help instructions for clarity

[macronym]

I was trying to learn how to use fierce and noticed the manpage can be improved to be more intuitive and clear.

Specifically, I noticed that the argument --traverse TRAVERSE doesn't clarify what form TRAVERSE should be. It could be changed to something like --traverse NUM and the description of it something like: "Perform a reverse DNS lookup on NUM IP addresses..."

Likewise for any other ambiguous arguments.

Debian has a downstream manpage for fierce here but they recommended I create the issue here.