updated README
updated README

zeke/geokit-rails,bellycard/geokit-acts-as-mappable,kidzui/geokit-rails3,jensb/geokit-rails,geokit/geokit-rails,Spindle-Inc/geokit-rails,jlecour/geokit-rails,BlinkerGit/geokit-rails,geokit/geokit-rails3,globalworks/geokit-rails3