transformer
https://blog.csdn.net/YQMind/article/details/80864133
https://zhuanlan.zhihu.com/p/54675834
https://blog.csdn.net/qq_41664845/article/details/84969266 #中文
https://jalammar.github.io/illustrated-transformer/ #英文
https://kexue.fm/archives/4765
https://blog.csdn.net/yiyele/article/details/81913031
https://blog.csdn.net/weixin_37947156/article/details/86255622
