update rank yaml, model, and add infer option in rank models (!21) · 合并请求 · PaddlePaddle / PaddleRec

update rank yaml, model, and add infer option in rank models !21

Created by: yaoxuefeng6

1, update yaml in rank models 2, update readme of rank to indicate the differences between running demo and paper reproduction 3, add infer option in rank models