Document max-pending as form of backpressure (closes Onyx#241)
Document max-pending as form of backpressure
(closes Onyx#241)

vijaykiran/onyx,KevinGreene/onyx,onyx-platform/onyx,mccraigmccraig/onyx,dignati/onyx,Deraen/onyx,iperdomo/onyx,ideal-knee/onyx