Update README.rdoc
Update README.rdoc

clarify that paginate_array does not work on the array inline, but instead returns a new PaginatableArray.
onursarikaya/kaminari,jcoyne/kaminari,thiagorp/kaminari,pat/kaminari,mperrando/kaminari,mrstif/cursor,jiamaozheng/kaminari,antstorm/kaminari,guodongme/kaminari,sachin21/kaminari,mrhead/kaminari,peter-umb/umbie_kaminari,amatsuda/kaminari,epicagency/kaminari,aelogica/kaminari,plribeiro3000/kaminari,parity/kaminari,JuanitoFatas/kaminari,wkirschbaum/kaminari,plribeiro3000/kaminari,Boomkat/kaminari,yui-knk/kaminari,mperrando/kaminari,pat/kaminari,fkagami/kaminari,barkbox/cursor,bsboris/kaminari,yui-knk/kaminari,aelogica/kaminari,kaminari/kaminari,peter-umb/umbie_kaminari,dblock/kaminari,iberianpig/kaminari,kaminari/kaminari,sr-education/kaminari,Zhomart/kaminari,Boomkat/kaminari,Teino1978-Corp/Teino1978-Corp-kaminari,sr-education/kaminari,varvet/kaminari,sachin21/kaminari,Teino1978-Corp/Teino1978-Corp-kaminari,onursarikaya/kaminari,sanrodari/kaminari,royels/kaminari,sideci-sample/sideci-sample-kaminari,epicagency/kaminari,amatsuda/kaminari,sendgrid/kaminari,bonekost/kaminari,danimashu/kaminari,joe1chen/kaminari,sanrodari/kaminari,danimashu/kaminari,sendgrid/kaminari,JuanitoFatas/kaminari,bonekost/kaminari,antstorm/kaminari,royels/kaminari,sendgrid/kaminari,jiamaozheng/kaminari,Zhomart/kaminari,dblock/kaminari,thiagorp/kaminari,mrhead/kaminari,wkirschbaum/kaminari,joe1chen/kaminari,bsboris/kaminari,varvet/kaminari,parity/kaminari,iberianpig/kaminari,guodongme/kaminari