Add command description and license info.

lib/geocoder/cli.rb

@@ -41,12 +41,15 @@ module Geocoder
         end
 
         opts.on_tail("-v", "--version", "Print version number") do
-          puts "Geocoder #{Geocoder.version}"
+          out << "Geocoder #{Geocoder.version}"
           exit
         end
 
         opts.on_tail("-h", "--help", "Print this help") do
-          puts opts
+          out << "Look up geographic information about a location.\n\n"
+          out << opts
+          out << "\n\nCreated and maintained by Alex Reisner, available under the MIT License.\n"
+          out << "Report bugs and contribute at http://github.com/alexreisner/geocoder\n"
           exit
         end
       }.parse!(args)