document the debug flag in the Cabal file
document the debug flag in the Cabal file

mikusp/accelerate-cuda,AccelerateHS/accelerate-cuda,mwu-tow/accelerate-cuda,mwu-tow/accelerate-cuda,flowbox-public/accelerate-cuda,mwu-tow/accelerate-cuda,mikusp/accelerate-cuda,mikusp/accelerate-cuda,flowbox-public/accelerate-cuda,AccelerateHS/accelerate-cuda,flowbox-public/accelerate-cuda,AccelerateHS/accelerate-cuda,tmcdonell/accelerate-cuda,tmcdonell/accelerate-cuda,tmcdonell/accelerate-cuda