Add tip about 'required' in sonata_type_collection
Add tip about 'required' in sonata_type_collection

Document 'required' option behavior in sonata_type_collection
nexylan/SonataAdminBundle,rmzamora/SonataAdminBundle,mohebifar/SonataAdminBundle,mohebifar/SonataAdminBundle,Armstrong1992/SonataAdminBundle,FabienD/SonataAdminBundle,rschumacher/SonataAdminBundle,gRoussac/SonataAdminBundle,binhle410/SonataAdminBundle,core23/SonataAdminBundle,gRoussac/SonataAdminBundle,ksom/SonataAdminBundle,j-ledoux/SonataAdminBundle,jakublech/SonataAdminBundle,claudusd/SonataAdminBundle,FabienD/SonataAdminBundle,arbislimen/SonataAdminBundle,mweimerskirch/SonataAdminBundle,Soullivaneuh/SonataAdminBundle,mikemeier/SonataAdminBundle,ejkun/SonataAdminBundle,Soullivaneuh/SonataAdminBundle,andythorne/SonataAdminBundle,ruscon/SonataAdminBundle,lightglitch/SonataAdminBundle,ksom/SonataAdminBundle,peter-gribanov/SonataAdminBundle,ju1ius/SonataAdminBundle,UnDeleteRU/SonataAdminBundle,ruscon/SonataAdminBundle,Storke/SonataAdminBundle,mgdigital/SonataAdminBundle,vincenttouzet/SonataAdminBundle,jszmidt/SonataAdminBundle,idchlife/SonataAdminBundle,ellementA/SonataAdminBundle,goldbroker/SonataAdminBundle,rswork/SonataAdminBundle,binhle410/SonataAdminBundle,rswork/SonataAdminBundle,ruscon/SonataAdminBundle,vincenttouzet/SonataAdminBundle,tim96/SonataAdminBundle,news-life-media/SonataAdminBundle,vincenttouzet/SonataAdminBundle,idchlife/SonataAdminBundle,news-life-media/SonataAdminBundle,lightglitch/SonataAdminBundle,j-ledoux/SonataAdminBundle,goldbroker/SonataAdminBundle,mohebifar/SonataAdminBundle,mweimerskirch/SonataAdminBundle,ju1ius/SonataAdminBundle,tim96/SonataAdminBundle,Armstrong1992/SonataAdminBundle,news-life-media/SonataAdminBundle,OskarStark/SonataAdminBundle,ossinkine/SonataAdminBundle,digitalkaoz/SonataAdminBundle,Romashka/SonataAdminBundle,amine2z/SonataAdminBundle,Romashka/SonataAdminBundle,jakublech/SonataAdminBundle,claudusd/SonataAdminBundle,robhunt3r/SonataAdminBundle,rschumacher/SonataAdminBundle,gnorby88/SonataAdminBundle,Th3Mouk/SonataAdminBundle,core23/SonataAdminBundle,UnDeleteRU/SonataAdminBundle,osavchenko/SonataAdminBundle,edouardkombo/SonataAdminBundle,Denniskevin/SonataAdminBundle,greg0ire/SonataAdminBundle,ellementA/SonataAdminBundle,morgangiraud/SonataAdminBundle,FabienD/SonataAdminBundle,0mars/SonataAdminBundle,fosvn/SonataAdminBundle,jakublech/SonataAdminBundle,ju1ius/SonataAdminBundle,ejkun/SonataAdminBundle,lightglitch/SonataAdminBundle,Soullivaneuh/SonataAdminBundle,Koc/SonataAdminBundle,gnorby88/SonataAdminBundle,claudusd/SonataAdminBundle,jlamur/SonataAdminBundle,binhle410/SonataAdminBundle,gnorby88/SonataAdminBundle,goldbroker/SonataAdminBundle,morgangiraud/SonataAdminBundle,jordisala1991/SonataAdminBundle,news-life-media/SonataAdminBundle,mikemeier/SonataAdminBundle,OskarStark/SonataAdminBundle,Denniskevin/SonataAdminBundle,nexylan/SonataAdminBundle,j-ledoux/SonataAdminBundle,sonata-project/SonataAdminBundle,rschumacher/SonataAdminBundle,lutangar/SonataAdminBundle,mikemeier/SonataAdminBundle,fosvn/SonataAdminBundle,joshlopes/SonataAdminBundle,osavchenko/SonataAdminBundle,amine2z/SonataAdminBundle,ossinkine/SonataAdminBundle,lutangar/SonataAdminBundle,ARTACK/SonataAdminBundle,Storke/SonataAdminBundle,rswork/SonataAdminBundle,rswork/SonataAdminBundle,Koc/SonataAdminBundle,mikemeier/SonataAdminBundle,fosvn/SonataAdminBundle,nexylan/SonataAdminBundle,UnDeleteRU/SonataAdminBundle,qsomazzi/SonataAdminBundle,Romashka/SonataAdminBundle,tim96/SonataAdminBundle,jlamur/SonataAdminBundle,core23/SonataAdminBundle,greg0ire/SonataAdminBundle,digitalkaoz/SonataAdminBundle,gnorby88/SonataAdminBundle,Koc/SonataAdminBundle,idchlife/SonataAdminBundle,UnDeleteRU/SonataAdminBundle,fosvn/SonataAdminBundle,ellementA/SonataAdminBundle,tskorupka/SonataAdminBundle,jordisala1991/SonataAdminBundle,dmarkowicz/SonataAdminBundle,osavchenko/SonataAdminBundle,ejkun/SonataAdminBundle,OskarStark/SonataAdminBundle,morfin60/SonataAdminBundle,ARTACK/SonataAdminBundle,jordisala1991/SonataAdminBundle,lightglitch/SonataAdminBundle,qsomazzi/SonataAdminBundle,peter-gribanov/SonataAdminBundle,gRoussac/SonataAdminBundle,ARTACK/SonataAdminBundle,Soullivaneuh/SonataAdminBundle,idchlife/SonataAdminBundle,rmzamora/SonataAdminBundle,nexylan/SonataAdminBundle,0mars/SonataAdminBundle,digitalkaoz/SonataAdminBundle,joshlopes/SonataAdminBundle,osavchenko/SonataAdminBundle,0mars/SonataAdminBundle,Romashka/SonataAdminBundle,cmacetko/SonataAdminBundle,ksom/SonataAdminBundle,andythorne/SonataAdminBundle,tskorupka/SonataAdminBundle,morfin60/SonataAdminBundle,ejkun/SonataAdminBundle,goldbroker/SonataAdminBundle,UnDeleteRU/SonataAdminBundle,arbislimen/SonataAdminBundle,Denniskevin/SonataAdminBundle,greg0ire/SonataAdminBundle,mohebifar/SonataAdminBundle,jordisala1991/SonataAdminBundle,ossinkine/SonataAdminBundle,ryanhughes/SonataAdminBundle,robhunt3r/SonataAdminBundle,tunne/SonataAdminBundle,jszmidt/SonataAdminBundle,jszmidt/SonataAdminBundle,ellementA/SonataAdminBundle,morfin60/SonataAdminBundle,morfin60/SonataAdminBundle,qsomazzi/SonataAdminBundle,joshlopes/SonataAdminBundle,tunne/SonataAdminBundle,binhle410/SonataAdminBundle,jlamur/SonataAdminBundle,mgdigital/SonataAdminBundle,dankempster/SonataAdminBundle,andythorne/SonataAdminBundle,amine2z/SonataAdminBundle,ellementA/SonataAdminBundle,ju1ius/SonataAdminBundle,ryanhughes/SonataAdminBundle,mweimerskirch/SonataAdminBundle,tskorupka/SonataAdminBundle,dmarkowicz/SonataAdminBundle,rschumacher/SonataAdminBundle,claudusd/SonataAdminBundle,dmarkowicz/SonataAdminBundle,mgdigital/SonataAdminBundle,Th3Mouk/SonataAdminBundle,jakublech/SonataAdminBundle,tim96/SonataAdminBundle,sonata-project/SonataAdminBundle,morgangiraud/SonataAdminBundle,ryanhughes/SonataAdminBundle,jszmidt/SonataAdminBundle,Th3Mouk/SonataAdminBundle,OskarStark/SonataAdminBundle,robhunt3r/SonataAdminBundle,tskorupka/SonataAdminBundle,0mars/SonataAdminBundle,peter-gribanov/SonataAdminBundle,arbislimen/SonataAdminBundle,osavchenko/SonataAdminBundle,lutangar/SonataAdminBundle,Storke/SonataAdminBundle,qsomazzi/SonataAdminBundle,jlamur/SonataAdminBundle,core23/SonataAdminBundle,andythorne/SonataAdminBundle,digitalkaoz/SonataAdminBundle,binhle410/SonataAdminBundle,ryanhughes/SonataAdminBundle,edouardkombo/SonataAdminBundle,amine2z/SonataAdminBundle,dankempster/SonataAdminBundle,cmacetko/SonataAdminBundle,lutangar/SonataAdminBundle,vincenttouzet/SonataAdminBundle,Th3Mouk/SonataAdminBundle,Denniskevin/SonataAdminBundle,ejkun/SonataAdminBundle,j-ledoux/SonataAdminBundle,news-life-media/SonataAdminBundle,gRoussac/SonataAdminBundle,edouardkombo/SonataAdminBundle,morfin60/SonataAdminBundle,morgangiraud/SonataAdminBundle,robhunt3r/SonataAdminBundle,j-ledoux/SonataAdminBundle,tunne/SonataAdminBundle,ruscon/SonataAdminBundle,dmarkowicz/SonataAdminBundle,ossinkine/SonataAdminBundle,joshlopes/SonataAdminBundle,peter-gribanov/SonataAdminBundle,cmacetko/SonataAdminBundle,jlamur/SonataAdminBundle,mweimerskirch/SonataAdminBundle,rmzamora/SonataAdminBundle,tunne/SonataAdminBundle,edouardkombo/SonataAdminBundle,ksom/SonataAdminBundle,greg0ire/SonataAdminBundle,Koc/SonataAdminBundle,Romashka/SonataAdminBundle,ARTACK/SonataAdminBundle,cmacetko/SonataAdminBundle,rmzamora/SonataAdminBundle,dmarkowicz/SonataAdminBundle,FabienD/SonataAdminBundle,dankempster/SonataAdminBundle,dankempster/SonataAdminBundle,Storke/SonataAdminBundle,mgdigital/SonataAdminBundle,arbislimen/SonataAdminBundle