Fix documentation for pluralization
Fix documentation for pluralization

The mentioned way of `DS.RESTAdapter.configure({ plurals: { ... } })` is being silently ignored. I figured this out from the tests, which are using the `DS.RESTAdapter.configure("plurals", { ... });` which works.
cyberkoi/website,shearwater-intl/website,EricSchank/website,AaronSikes/website,maczniak/emberjs,kkenan/website,davidpett/website,zeppelin/emberjs-website,cyberkoi/website,raycohen/website,greyhwndz/website,AgilionApps/website,shearwater-intl/website,praxxis/website,tmock12/website,mrjavascript/website,quangv/website,SaladFork/emberjs-website,wifelette/website,quangv/website,wifelette/website,zeppelin/emberjs-website,elidupuis/website,koriroys/emberjs-website,duggiefresh/website,quangv/website,koriroys/emberjs-website,MinxianLi/ember,bmac/website,datajohnny/website,jimmay5469/website,davidpett/website,SaladFork/emberjs-website,balupton/ember-website,SaladFork/emberjs-website,MinxianLi/ember,Eric-Guo/website,balupton/ember-website,MinxianLi/ember,josemarluedke/ember-website,AaronSikes/website,zeppelin/emberjs-website,josemarluedke/ember-website,SaladFork/emberjs-website,cllns/emberjs-website,Nick-Cotter/aboutme,bmac/website,zeppelin/emberjs-website,AaronSikes/website,Nick-Cotter/aboutme,cyberkoi/website,martndemus/website,tmock12/website,kpfefferle/website,maczniak/emberjs,balupton/ember-website,rwjblue/website,ktornwall/website,greyhwndz/website,kkenan/website,datajohnny/website,EricSchank/website,shama/website,AgilionApps/website,jimmay5469/website,Eric-Guo/website,EricSchank/website,kpfefferle/website,cllns/emberjs-website,knownasilya/website,workmanw/ember-website,shama/website,kpfefferle/website,workmanw/ember-website,ktornwall/website,duggiefresh/website,maxcal/website,jimmay5469/website,tmock12/website,ktornwall/website,maxcal/website,datajohnny/website,elwayman02/website,greyhwndz/website,martndemus/website,elwayman02/website,davidpett/website,duggiefresh/website,workmanw/ember-website,rwjblue/website,elidupuis/website,workmanw/ember-website,mrjavascript/website,bmac/website,praxxis/website,kkenan/website,Eric-Guo/website,maxcal/website,AgilionApps/website,martndemus/website,shearwater-intl/website,bmac/website,josemarluedke/ember-website,koriroys/emberjs-website,knownasilya/website,raycohen/website,wifelette/website,elwayman02/website,raycohen/website,elidupuis/website,cllns/emberjs-website,josemarluedke/ember-website,mrjavascript/website