add charset documentation in doctrine provider
add charset documentation in doctrine provider

lokhman/Silex,akucherevskiy/developex_test,plotek/Silex,mathroc/Silex,SpacePossum/Silex,Tobion/Silex,akucherevskiy/developex_test,cgsmith/Silex,naderman/Silex,jdreesen/Silex,silexphp/Silex,naderman/Silex,gencer/Silex,tcx1000/Silex,mathroc/Silex,romainneutron/Silex,Xephi/Silex,SanderKnape/Silex,SpacePossum/Silex,jdreesen/Silex,GromNaN/Silex,peterkokot/Silex,cesarmarinhorj/Silex,mTorres/Silex,naderman/Silex,RayRutjes/Silex,JPry/Silex,arduanov/Silex,Tobion/Silex,beealone/Silex,CarsonF/Silex,fhinkel/Silex,romainneutron/Silex,peterkokot/Silex,romainneutron/Silex,GromNaN/Silex,mmauri04/Silex,fhinkel/Silex,Incognito/silex-fork,GromNaN/Silex,mTorres/Silex,RayRutjes/Silex,peterkokot/Silex,arduanov/Silex,CarsonF/Silex,Xephi/Silex,SanderKnape/Silex,CarsonF/Silex,Incognito/silex-fork,Tobion/Silex,cesarmarinhorj/Silex,beealone/Silex,akucherevskiy/developex_test,lokhman/Silex,fabpot/Silex,JPry/Silex,cgsmith/Silex,tcx1000/Silex,plotek/Silex,fabpot/Silex,mmauri04/Silex