added section on recipients.yaml. added docs on writing notifiers
added section on recipients.yaml. added docs on writing notifiers

flapjack/flapjack,flapjack/flapjack,necula01/flapjack,flapjack/flapjack,flapjack/flapjack,ikusalic/flapjack,cloudevelops/flapjack,necula01/flapjack,cloudevelops/flapjack,ikusalic/flapjack,cloudevelops/flapjack,ikusalic/flapjack,necula01/flapjack,flapjack/flapjack,ikusalic/flapjack,necula01/flapjack,ikusalic/flapjack,necula01/flapjack,cloudevelops/flapjack