Expand on within_bounding_box documentation.
Expand on within_bounding_box documentation.

Also move it to a new "Advanced Querying" section.

TrangPham/geocoder,mehlah/geocoder,rios1993/geocoder,Devetzis/geocoder,sr-education/geocoder,StudioMelipone/geocoder,eugenehp/ruby-geocoder,epyatopal/geocoder,ivanzotov/geocoder,GermanDZ/geocoder,gogovan/geocoder-olleh,alexreisner/geocoder,AndyDangerous/geocoder,moofish32/geocoder,mveer99/geocoder,jaigouk/geocoder-olleh,rdlugosz/geocoder,andreamazz/geocoder,ankane/geocoder,guavapass/geocoder,FanaHOVA/geocoder,donbobka/geocoder,brian-ewell/geocoder,boone/geocoder,jgrciv/geocoder,sideci-sample/sideci-sample-geocoder,3mundi/geocoder,tiramizoo/geocoder,davydovanton/geocoder,crdunwel/geocoder,gogovan/geocoder-olleh,mdebo/geocoder,aceunreal/geocoder,rayzeller/geocoder,nerdyglasses/geocoder,sjaveed/geocoder,tortuba/geocoder,jaigouk/geocoder-olleh,malandrina/geocoder