[Documentation] fix typo in fixture docs
[Documentation] fix typo in fixture docs

Removed the word "extended" that was used twice
Zales0123/Sylius,diimpp/Sylius,mbabker/Sylius,antonioperic/Sylius,antonioperic/Sylius,SyliusBot/Sylius,lchrusciel/Sylius,loic425/Sylius,Sylius/Sylius,pamil/Sylius,GSadee/Sylius,Arminek/Sylius,lchrusciel/Sylius,diimpp/Sylius,loic425/Sylius,Arminek/Sylius,pjedrzejewski/Sylius,kayue/Sylius,SyliusBot/Sylius,lchrusciel/Sylius,pamil/Sylius,diimpp/Sylius,101medialab/Sylius,101medialab/Sylius,pjedrzejewski/Sylius,GSadee/Sylius,pjedrzejewski/Sylius,SyliusBot/Sylius,Sylius/Sylius,Zales0123/Sylius,loic425/Sylius,kayue/Sylius,101medialab/Sylius,pamil/Sylius,mbabker/Sylius,antonioperic/Sylius,Sylius/Sylius,mbabker/Sylius,Arminek/Sylius,Zales0123/Sylius,kayue/Sylius,GSadee/Sylius,pjedrzejewski/Sylius,mbabker/Sylius