Add section about igDataSource into the README
Add section about igDataSource into the README

IgniteUI/igniteui-angular2,dkamburov/igniteui-angular2,IgniteUI/igniteui-angular2,MayaKirova/igniteui-angular2,dkamburov/igniteui-angular2,MayaKirova/igniteui-angular2,dkamburov/igniteui-angular2,MayaKirova/igniteui-angular2,IgniteUI/igniteui-angular2