readme: add mail list and archive

README.md

@@ -6,11 +6,14 @@ XiangShan (香山) is an open-source high-performance RISC-V processor project.
 
 Copyright 2020-2021 by Institute of Computing Technology, Chinese Academy of Sciences.
 
-# Docs and slides
+## Docs and slides
 We gave 20+ presentations on RISC-V World Conference China 2021. XiangShan tutorial was held at the same place. Our slides for RVWC2021 have been updated on [our doc repo](https://github.com/OpenXiangShan/XiangShan-doc) (in Chinese).
 
 我们在2021年RISC-V中国峰会的报告已经更新到[这里](https://github.com/OpenXiangShan/XiangShan-doc)。未来的文档和相关信息也将更新到相同的仓库。
 
+## Mail list
+You can contact us through [our mail list](mailto:[email protected]). All mails from this list will be archived to [here](https://www.mail-archive.com/[email protected]/).
+
 ## Architecture
 
 The first stable micro-architecture of XiangShan is called Yanqihu (雁栖湖) on this [branch](https://github.com/OpenXiangShan/XiangShan/tree/yanqihu), which has been developed since June 2020. The current version of XiangShan, also known as Nanhu (南湖), is still under development on the master branch.

readme.zh-cn.md

@@ -13,6 +13,9 @@ English Readme is [here](README.md).
 
 未来更多的文档也将更新到相同的仓库。
 
+## 邮件列表
+可以通过[我们的邮件列表](mailto:[email protected])联系我们。列表中的所有邮件会存档到[这里](https://www.mail-archive.com/[email protected]/)。
+
 ## 处理器架构
 
 自 2020 年 6 月开始开发的[雁栖湖](https://github.com/OpenXiangShan/XiangShan/tree/yanqihu)为香山处理器的首个稳定的微架构。目前版本的香山（即南湖）正在 master 分支上不断开发中。