Fix some errors in the Block design doc (#7460)
Fix some errors in the Block design doc (#7460)


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