Update getting_started.rst
Update getting_started.rst

We have an errors without this two additional strings.
These strings from Symfony Coockbook (http://symfony.com/doc/current/cookbook/bundles/extension.html)
sonata-project/SonataAdminBundle,ejkun/SonataAdminBundle,ossinkine/SonataAdminBundle,jlamur/SonataAdminBundle,robhunt3r/SonataAdminBundle,binhle410/SonataAdminBundle,ju1ius/SonataAdminBundle,goldbroker/SonataAdminBundle,mweimerskirch/SonataAdminBundle,rswork/SonataAdminBundle,osavchenko/SonataAdminBundle,jlamur/SonataAdminBundle,ejkun/SonataAdminBundle,news-life-media/SonataAdminBundle,Soullivaneuh/SonataAdminBundle,Romashka/SonataAdminBundle,morfin60/SonataAdminBundle,dankempster/SonataAdminBundle,idchlife/SonataAdminBundle,idchlife/SonataAdminBundle,news-life-media/SonataAdminBundle,rmzamora/SonataAdminBundle,OskarStark/SonataAdminBundle,rswork/SonataAdminBundle,ellementA/SonataAdminBundle,morfin60/SonataAdminBundle,robhunt3r/SonataAdminBundle,ARTACK/SonataAdminBundle,goldbroker/SonataAdminBundle,rswork/SonataAdminBundle,idchlife/SonataAdminBundle,greg0ire/SonataAdminBundle,UnDeleteRU/SonataAdminBundle,qsomazzi/SonataAdminBundle,tim96/SonataAdminBundle,rmzamora/SonataAdminBundle,robhunt3r/SonataAdminBundle,goldbroker/SonataAdminBundle,ARTACK/SonataAdminBundle,Th3Mouk/SonataAdminBundle,morfin60/SonataAdminBundle,dmarkowicz/SonataAdminBundle,rswork/SonataAdminBundle,ARTACK/SonataAdminBundle,ossinkine/SonataAdminBundle,dmarkowicz/SonataAdminBundle,goldbroker/SonataAdminBundle,osavchenko/SonataAdminBundle,news-life-media/SonataAdminBundle,digitalkaoz/SonataAdminBundle,peter-gribanov/SonataAdminBundle,jordisala1991/SonataAdminBundle,ellementA/SonataAdminBundle,Soullivaneuh/SonataAdminBundle,j-ledoux/SonataAdminBundle,Romashka/SonataAdminBundle,rmzamora/SonataAdminBundle,lutangar/SonataAdminBundle,peter-gribanov/SonataAdminBundle,jordisala1991/SonataAdminBundle,ellementA/SonataAdminBundle,tim96/SonataAdminBundle,vincenttouzet/SonataAdminBundle,amine2z/SonataAdminBundle,greg0ire/SonataAdminBundle,dankempster/SonataAdminBundle,tskorupka/SonataAdminBundle,amine2z/SonataAdminBundle,osavchenko/SonataAdminBundle,Th3Mouk/SonataAdminBundle,ju1ius/SonataAdminBundle,UnDeleteRU/SonataAdminBundle,Koc/SonataAdminBundle,ju1ius/SonataAdminBundle,lutangar/SonataAdminBundle,rmzamora/SonataAdminBundle,Koc/SonataAdminBundle,qsomazzi/SonataAdminBundle,mikemeier/SonataAdminBundle,Koc/SonataAdminBundle,Romashka/SonataAdminBundle,digitalkaoz/SonataAdminBundle,mikemeier/SonataAdminBundle,tskorupka/SonataAdminBundle,greg0ire/SonataAdminBundle,j-ledoux/SonataAdminBundle,morfin60/SonataAdminBundle,Armstrong1992/SonataAdminBundle,dmarkowicz/SonataAdminBundle,amine2z/SonataAdminBundle,ARTACK/SonataAdminBundle,dankempster/SonataAdminBundle,osavchenko/SonataAdminBundle,ossinkine/SonataAdminBundle,jlamur/SonataAdminBundle,qsomazzi/SonataAdminBundle,binhle410/SonataAdminBundle,qsomazzi/SonataAdminBundle,vincenttouzet/SonataAdminBundle,binhle410/SonataAdminBundle,lutangar/SonataAdminBundle,Th3Mouk/SonataAdminBundle,news-life-media/SonataAdminBundle,Soullivaneuh/SonataAdminBundle,dankempster/SonataAdminBundle,j-ledoux/SonataAdminBundle,Soullivaneuh/SonataAdminBundle,Romashka/SonataAdminBundle,jordisala1991/SonataAdminBundle,dmarkowicz/SonataAdminBundle,UnDeleteRU/SonataAdminBundle,vincenttouzet/SonataAdminBundle,j-ledoux/SonataAdminBundle,jordisala1991/SonataAdminBundle,OskarStark/SonataAdminBundle,ellementA/SonataAdminBundle,vincenttouzet/SonataAdminBundle,Armstrong1992/SonataAdminBundle,jlamur/SonataAdminBundle,idchlife/SonataAdminBundle,ju1ius/SonataAdminBundle,dmarkowicz/SonataAdminBundle,sonata-project/SonataAdminBundle,greg0ire/SonataAdminBundle,ejkun/SonataAdminBundle,tim96/SonataAdminBundle,mweimerskirch/SonataAdminBundle,lutangar/SonataAdminBundle,mikemeier/SonataAdminBundle,UnDeleteRU/SonataAdminBundle,amine2z/SonataAdminBundle,mweimerskirch/SonataAdminBundle,digitalkaoz/SonataAdminBundle,Th3Mouk/SonataAdminBundle,OskarStark/SonataAdminBundle,ejkun/SonataAdminBundle,osavchenko/SonataAdminBundle,tskorupka/SonataAdminBundle,mikemeier/SonataAdminBundle,Koc/SonataAdminBundle,jlamur/SonataAdminBundle,UnDeleteRU/SonataAdminBundle,news-life-media/SonataAdminBundle,tskorupka/SonataAdminBundle,binhle410/SonataAdminBundle,Romashka/SonataAdminBundle,ejkun/SonataAdminBundle,ossinkine/SonataAdminBundle,peter-gribanov/SonataAdminBundle,peter-gribanov/SonataAdminBundle,OskarStark/SonataAdminBundle,morfin60/SonataAdminBundle,tim96/SonataAdminBundle,binhle410/SonataAdminBundle,mweimerskirch/SonataAdminBundle,digitalkaoz/SonataAdminBundle,j-ledoux/SonataAdminBundle,ellementA/SonataAdminBundle,robhunt3r/SonataAdminBundle