OPD学习笔记

学习OPD并复现。参考资料：https://github.com/david-xinyuwei/david-share/blob/master/DL-Algorithm-Insights/Multi-Expert-OPD-Distillation/README-CN.md，https://github.com/david-xinyuwei/david-share/tree/master/DL-Algorithm-Insights。

一些启发

1. 作者讨论的"为什么是on-policy 而不是 sft？"
   见https://github.com/david-xinyuwei/david-share/blob/master/DL-Algorithm-Insights/Multi-Expert-OPD-Distillation/README-CN.md "vs SFT（Supervised Fine-Tuning）------ Exposure Bias 问题"