Basic documentation update for map.rb
Basic documentation update for map.rb

gravitystorm/Ruby-Mapnik,gravitystorm/Ruby-Mapnik,mapnik/Ruby-Mapnik,gravitystorm/Ruby-Mapnik,mapnik/Ruby-Mapnik,gravitystorm/Ruby-Mapnik,mapnik/Ruby-Mapnik,mapnik/Ruby-Mapnik,gravitystorm/Ruby-Mapnik,gravitystorm/Ruby-Mapnik,mapnik/Ruby-Mapnik,mapnik/Ruby-Mapnik