LKV

Results 3 issues of LKV

![image](https://user-images.githubusercontent.com/87376138/223173386-b461bce5-6e62-4329-912b-69531dea8e53.png) 似乎没有实现latex公式渲染,如果能加上就更好了!

I want to finetune on 3090*4/8 (stage two), but there is not enough VRAM... Is there any way to perform finetuning in these circumstances?

Thank you for your outstanding work! In the second stage of training, I commented out max_txt_len and the memory usage decreased by 10G (from 60G to 50G, A100). I want...