add rnn_design.md
add rnn_design.md

pkuyym/Paddle,reyoung/Paddle,lcy-seso/Paddle,putcn/Paddle,lispc/Paddle,pengli09/Paddle,lispc/Paddle,jacquesqiao/Paddle,tensor-tang/Paddle,reyoung/Paddle,QiJune/Paddle,lcy-seso/Paddle,QiJune/Paddle,yu239/Paddle,chengduoZH/Paddle,Canpio/Paddle,chengduoZH/Paddle,PaddlePaddle/Paddle,lcy-seso/Paddle,QiJune/Paddle,luotao1/Paddle,chengduoZH/Paddle,yu239/Paddle,Canpio/Paddle,lcy-seso/Paddle,Canpio/Paddle,lispc/Paddle,jacquesqiao/Paddle,lispc/Paddle,lispc/Paddle,Canpio/Paddle,hedaoyuan/Paddle,Canpio/Paddle,putcn/Paddle,tensor-tang/Paddle,baidu/Paddle,QiJune/Paddle,pkuyym/Paddle,baidu/Paddle,putcn/Paddle,putcn/Paddle,PaddlePaddle/Paddle,PaddlePaddle/Paddle,Canpio/Paddle,pengli09/Paddle,pengli09/Paddle,reyoung/Paddle,yu239/Paddle,PaddlePaddle/Paddle,QiJune/Paddle,hedaoyuan/Paddle,hedaoyuan/Paddle,lispc/Paddle,tensor-tang/Paddle,hedaoyuan/Paddle,putcn/Paddle,pkuyym/Paddle,pengli09/Paddle,chengduoZH/Paddle,luotao1/Paddle,reyoung/Paddle,luotao1/Paddle,PaddlePaddle/Paddle,Canpio/Paddle,PaddlePaddle/Paddle,jacquesqiao/Paddle,pkuyym/Paddle,hedaoyuan/Paddle,hedaoyuan/Paddle,luotao1/Paddle,pkuyym/Paddle,lcy-seso/Paddle,hedaoyuan/Paddle,putcn/Paddle,jacquesqiao/Paddle,reyoung/Paddle,yu239/Paddle,hedaoyuan/Paddle,jacquesqiao/Paddle,baidu/Paddle,pengli09/Paddle,lispc/Paddle,baidu/Paddle,jacquesqiao/Paddle,pengli09/Paddle,tensor-tang/Paddle,chengduoZH/Paddle,yu239/Paddle,lispc/Paddle,PaddlePaddle/Paddle,yu239/Paddle,pengli09/Paddle,luotao1/Paddle,Canpio/Paddle,pkuyym/Paddle,luotao1/Paddle,pengli09/Paddle,yu239/Paddle,luotao1/Paddle,yu239/Paddle,reyoung/Paddle,lcy-seso/Paddle,tensor-tang/Paddle,QiJune/Paddle,baidu/Paddle