[Docs][Book][Products] Product associations - review fixes
[Docs][Book][Products] Product associations - review fixes

lchrusciel/Sylius,SyliusBot/Sylius,antonioperic/Sylius,diimpp/Sylius,loic425/Sylius,Zales0123/Sylius,antonioperic/Sylius,101medialab/Sylius,SyliusBot/Sylius,SyliusBot/Sylius,loic425/Sylius,loic425/Sylius,Sylius/Sylius,Sylius/Sylius,101medialab/Sylius,101medialab/Sylius,diimpp/Sylius,Sylius/Sylius,antonioperic/Sylius,Zales0123/Sylius,diimpp/Sylius,lchrusciel/Sylius,Zales0123/Sylius,lchrusciel/Sylius