Update index.md
Update index.md

Add details about $ionicConfigProvider.views.forwardCache(true); since it's not apparent on this page that this is available.
johnli388/ionic-site,martinjbaker/ionic-site,ionic-team/ionic-site,driftyco/ionic-site,driftyco/ionic-site,qintengfei/ionic-site,thiagofelix/ionic-site,saimandeper/ionic-site,stianjensen/ionic-site,martinjbaker/ionic-site,ionic-team/ionic-site,johnli388/ionic-site,philmerrell/ionic-site,thiagofelix/ionic-site,stianjensen/ionic-site,sachinvettithanam/ionic-site,johnli388/ionic-site,ionic-team/ionic-site,driftyco/ionic-site,philmerrell/ionic-site,qintengfei/ionic-site,saimandeper/ionic-site,sachinvettithanam/ionic-site,thiagofelix/ionic-site,saimandeper/ionic-site,stianjensen/ionic-site,driftyco/ionic-site,sachinvettithanam/ionic-site,ionic-team/ionic-site,driftyco/ionic-site,qintengfei/ionic-site,martinjbaker/ionic-site,philmerrell/ionic-site