add a stop/limit mechanism for trading in pancakeswap

this is a suggest to add stop and limit mechanism(like some centralizaed exchanges have, binance for example) in pancakeswap so we dont have to buy only at market price, just simply lock our founds and when the price reaches the target, buy or sell, This would make pancakeswap more usefull, get new user and probably increase the price of cake and help burn it.