Update configuration.rst
Update configuration.rst

* Add promotion_subject classes
* Add missing validation groups
bitbager/Sylius,gabiudrescu/Sylius,foobarflies/Sylius,antonioperic/Sylius,Sylius/Sylius,kayue/Sylius,GSadee/Sylius,TheMadeleine/Sylius,SyliusBot/Sylius,tuka217/Sylius,Zales0123/Sylius,pjedrzejewski/Sylius,Niiko/Sylius,Pitoune/Sylius,Ejobs/Sylius,davalb/Sylius,loic425/Sylius,lchrusciel/Sylius,TheMadeleine/Sylius,ReissClothing/Sylius,gabiudrescu/Sylius,cdaguerre/Sylius,DorianCMore/Sylius,patrick-mcdougle/Sylius,juramy/Sylius,Lowlo/Sylius,juramy/Sylius,bretto36/Sylius,ylastapis/Sylius,101medialab/Sylius,mheki/Sylius,ReissClothing/Sylius,CoderMaggie/Sylius,torinaki/Sylius,Brille24/Sylius,101medialab/Sylius,gruberro/Sylius,jjanvier/Sylius,danut007ro/Sylius,gorkalaucirica/Sylius,MichaelKubovic/Sylius,ktzouno/Sylius,axelvnk/Sylius,cdaguerre/Sylius,adamelso/Sylius,mbabker/Sylius,itinance/Sylius,TeamNovatek/Sylius,bretto36/Sylius,fredcollet/Sylius,polisys/Sylius,bretto36/Sylius,Joypricecorp/Sylius,Rvanlaak/Sylius,dragosprotung/Sylius,pjedrzejewski/Sylius,venyii/Sylius,pamil/Sylius,michalmarcinkowski/Sylius,coudenysj/Sylius,ReissClothing/Sylius,Sylius/Sylius,torinaki/Sylius,sweoggy/Sylius,gseidel/Sylius,PyRowMan/Sylius,Mozan/Sylius,vihuvac/Sylius,CoderMaggie/Sylius,fredcollet/Sylius,nakashu/Sylius,danut007ro/Sylius,davalb/Sylius,sweoggy/Sylius,Niiko/Sylius,diimpp/Sylius,tuka217/Sylius,Mozan/Sylius,bitbager/Sylius,inssein/Sylius,pamil/Sylius,adamelso/Sylius,PyRowMan/Sylius,mbabker/Sylius,coudenysj/Sylius,fredcollet/Sylius,itinance/Sylius,ylastapis/Sylius,Ejobs/Sylius,psren/Sylius,mheki/Sylius,adamelso/Sylius,patrick-mcdougle/Sylius,ravaj-group/Sylius,MichaelKubovic/Sylius,TeamNovatek/Sylius,ravaj-group/Sylius,Ejobs/Sylius,nakashu/Sylius,michalmarcinkowski/Sylius,rpg600/Sylius,ravaj-group/Sylius,inssein/Sylius,tuka217/Sylius,CoderMaggie/Sylius,Niiko/Sylius,jjanvier/Sylius,DorianCMore/Sylius,psren/Sylius,101medialab/Sylius,patrick-mcdougle/Sylius,psyray/Sylius,bitbager/Sylius,Mozan/Sylius,DorianCMore/Sylius,psren/Sylius,juramy/Sylius,jjanvier/Sylius,pjedrzejewski/Sylius,venyii/Sylius,ReissClothing/Sylius,Mozan/Sylius,torinaki/Sylius,patrick-mcdougle/Sylius,bretto36/Sylius,videni/Sylius,Zales0123/Sylius,videni/Sylius,gruberro/Sylius,GSadee/Sylius,TeamNovatek/Sylius,Joypricecorp/Sylius,Mozan/Sylius,juramy/Sylius,kayue/Sylius,michalmarcinkowski/Sylius,fredcollet/Sylius,gorkalaucirica/Sylius,ravaj-group/Sylius,Rvanlaak/Sylius,tuka217/Sylius,videni/Sylius,Joypricecorp/Sylius,polisys/Sylius,PyRowMan/Sylius,axelvnk/Sylius,ravaj-group/Sylius,okwinza/Sylius,polisys/Sylius,mheki/Sylius,jjanvier/Sylius,foobarflies/Sylius,regnisolbap/Sylius,axelvnk/Sylius,gmoigneu/platformsh-integrations,davalb/Sylius,ReissClothing/Sylius,Brille24/Sylius,adamelso/Sylius,steffenbrem/Sylius,psyray/Sylius,cdaguerre/Sylius,Ejobs/Sylius,okwinza/Sylius,lchrusciel/Sylius,gseidel/Sylius,NeverResponse/Sylius,Rvanlaak/Sylius,Lowlo/Sylius,ylastapis/Sylius,patrick-mcdougle/Sylius,gmoigneu/platformsh-integrations,Brille24/Sylius,diimpp/Sylius,okwinza/Sylius,regnisolbap/Sylius,davalb/Sylius,videni/Sylius,steffenbrem/Sylius,coudenysj/Sylius,axelvnk/Sylius,SyliusBot/Sylius,vihuvac/Sylius,gruberro/Sylius,ezecosystem/Sylius,inssein/Sylius,polisys/Sylius,Arminek/Sylius,michalmarcinkowski/Sylius,TheMadeleine/Sylius,Pitoune/Sylius,ylastapis/Sylius,ezecosystem/Sylius,gmoigneu/platformsh-integrations,antonioperic/Sylius,vihuvac/Sylius,Joypricecorp/Sylius,axelvnk/Sylius,PyRowMan/Sylius,ktzouno/Sylius,sweoggy/Sylius,nakashu/Sylius,mheki/Sylius,pamil/Sylius,SyliusBot/Sylius,rpg600/Sylius,dragosprotung/Sylius,Pitoune/Sylius,NeverResponse/Sylius,Pitoune/Sylius,okwinza/Sylius,foobarflies/Sylius,fredcollet/Sylius,pjedrzejewski/Sylius,danut007ro/Sylius,jvahldick/Sylius,jvahldick/Sylius,mkilmanas/Sylius,mbabker/Sylius,regnisolbap/Sylius,Sylius/Sylius,jvahldick/Sylius,vihuvac/Sylius,nakashu/Sylius,rpg600/Sylius,TeamNovatek/Sylius,dragosprotung/Sylius,jvahldick/Sylius,polisys/Sylius,diimpp/Sylius,steffenbrem/Sylius,GSadee/Sylius,Zales0123/Sylius,mbabker/Sylius,gorkalaucirica/Sylius,gseidel/Sylius,CoderMaggie/Sylius,Arminek/Sylius,psyray/Sylius,TheMadeleine/Sylius,mkilmanas/Sylius,gmoigneu/platformsh-integrations,davalb/Sylius,Brille24/Sylius,ezecosystem/Sylius,ktzouno/Sylius,NeverResponse/Sylius,venyii/Sylius,steffenbrem/Sylius,antonioperic/Sylius,loic425/Sylius,gruberro/Sylius,inssein/Sylius,gabiudrescu/Sylius,psyray/Sylius,itinance/Sylius,kayue/Sylius,jjanvier/Sylius,rpg600/Sylius,foobarflies/Sylius,DorianCMore/Sylius,coudenysj/Sylius,juramy/Sylius,Arminek/Sylius,cdaguerre/Sylius,Rvanlaak/Sylius,lchrusciel/Sylius,Ejobs/Sylius,adamelso/Sylius,MichaelKubovic/Sylius,ezecosystem/Sylius,rpg600/Sylius,Niiko/Sylius,gseidel/Sylius,steffenbrem/Sylius,mkilmanas/Sylius,torinaki/Sylius,tuka217/Sylius,loic425/Sylius,psyray/Sylius,MichaelKubovic/Sylius,bitbager/Sylius,NeverResponse/Sylius,gorkalaucirica/Sylius,Rvanlaak/Sylius,danut007ro/Sylius,mkilmanas/Sylius,cdaguerre/Sylius,TeamNovatek/Sylius,itinance/Sylius,psren/Sylius,Lowlo/Sylius,dragosprotung/Sylius,coudenysj/Sylius,sweoggy/Sylius,Lowlo/Sylius,okwinza/Sylius,gabiudrescu/Sylius,regnisolbap/Sylius,ktzouno/Sylius,venyii/Sylius