Made macro doc clearer
Made macro doc clearer

Previous wording implied (to me at least) that macros *are* PHP functions.
derickr/Twig,peterkokot/Twig,hason/Twig,znerol/Twig,gencer/Twig,moltin/Twig,craue/Twig,nicolas-grekas/Twig,dkarvounaris/Twig,nicolas-grekas/Twig,Tobion/Twig,Tobion/Twig,Rvanlaak/Twig,hason/Twig,fsw/Twig,moltin/Twig,craue/Twig,hhamon/Twig,robregonm/Twig,iKwinto/Twig,fsw/Twig,moufmouf/Twig,apishka/templater,moufmouf/Twig,bocharsky-bw/Twig,jamessingizi/Twig,bocharsky-bw/Twig,hason/Twig,nicolas-grekas/Twig,framewr/Twig,apishka/templater,twigphp/Twig,Tobion/Twig,dkarvounaris/Twig,framewr/Twig,znerol/Twig,phansys/Twig,jamessingizi/Twig,jamessingizi/Twig,gamernetwork/Twig,dkarvounaris/Twig,gamernetwork/Twig,moltin/Twig,gamernetwork/Twig,znerol/Twig,gencer/Twig,markstory/Twig,twigphp/Twig,iKwinto/Twig,moufmouf/Twig,loi-chuanoi/Twig,robregonm/Twig,markstory/Twig,fsw/Twig,Rvanlaak/Twig,robregonm/Twig,framewr/Twig,hhamon/Twig,nicolas-grekas/Twig,huang53798584/Twig,derickr/Twig,bocharsky-bw/Twig,twigphp/Twig,hhamon/Twig,Rvanlaak/Twig,huang53798584/Twig,nicolas-grekas/Twig,phansys/Twig,huang53798584/Twig,iKwinto/Twig,peterkokot/Twig,derickr/Twig