added a paragraph in the docs about how the Twig blocks work (based on an explanation from nikic, closes #704, refs #351)
added a paragraph in the docs about how the Twig blocks work (based on an explanation from nikic, closes #704, refs #351)

hason/Twig,gamernetwork/Twig,moufmouf/Twig,iKwinto/Twig,huang53798584/Twig,bocharsky-bw/Twig,bocharsky-bw/Twig,moltin/Twig,huang53798584/Twig,huang53798584/Twig,znerol/Twig,znerol/Twig,gamernetwork/Twig,moufmouf/Twig,twigphp/Twig,twigphp/Twig,loi-chuanoi/Twig,Tobion/Twig,Rvanlaak/Twig,jamessingizi/Twig,apishka/templater,dkarvounaris/Twig,nicolas-grekas/Twig,gamernetwork/Twig,craue/Twig,derickr/Twig,moufmouf/Twig,nicolas-grekas/Twig,dkarvounaris/Twig,jamessingizi/Twig,derickr/Twig,dkarvounaris/Twig,phansys/Twig,hason/Twig,phansys/Twig,Rvanlaak/Twig,gencer/Twig,fsw/Twig,craue/Twig,twigphp/Twig,Tobion/Twig,moltin/Twig,markstory/Twig,Tobion/Twig,znerol/Twig,apishka/templater,robregonm/Twig,nicolas-grekas/Twig,framewr/Twig,hhamon/Twig,derickr/Twig,bocharsky-bw/Twig,framewr/Twig,robregonm/Twig,moltin/Twig,hason/Twig,fsw/Twig,hhamon/Twig,peterkokot/Twig,nicolas-grekas/Twig,jamessingizi/Twig,iKwinto/Twig,markstory/Twig,iKwinto/Twig,fsw/Twig,Rvanlaak/Twig,robregonm/Twig,nicolas-grekas/Twig,framewr/Twig,peterkokot/Twig,hhamon/Twig,gencer/Twig