Add language switch links to README files

Added cross-links between English and Chinese README files for easier language switching. Updated CODE_OF_CONDUCT.md to use angle brackets for email and URLs for improved formatting.

CODE_OF_CONDUCT.md

@@ -60,7 +60,7 @@ representative at an online or offline event.
 
 Instances of abusive, harassing, or otherwise unacceptable behavior may be
 reported to the community leaders responsible for enforcement at
-i@xi-xu.me.
+<i@xi-xu.me>.
 All complaints will be reviewed and investigated promptly and fairly.
 
 All community leaders are obligated to respect the privacy and security of the
@@ -116,13 +116,13 @@ the community.
 
 This Code of Conduct is adapted from the [Contributor Covenant][homepage],
 version 2.0, available at
-https://www.contributor-covenant.org/version/2/0/code_of_conduct.html.
+<https://www.contributor-covenant.org/version/2/0/code_of_conduct.html>.
 
 Community Impact Guidelines were inspired by [Mozilla's code of conduct
 enforcement ladder](https://github.com/mozilla/diversity).
 
-[homepage]: https://www.contributor-covenant.org
-
 For answers to common questions about this code of conduct, see the FAQ at
-https://www.contributor-covenant.org/faq. Translations are available at
-https://www.contributor-covenant.org/translations.
+<https://www.contributor-covenant.org/faq>. Translations are available at
+<https://www.contributor-covenant.org/translations>.
+
+[homepage]: https://www.contributor-covenant.org

README.md

@@ -1,5 +1,7 @@
 # DeepLX
 
+***[汉语](README.zh.md)***
+
 [![License](https://img.shields.io/github/license/xixu-me/deeplx)](#-license)
 [![Deployment Status](https://img.shields.io/website?url=https://dplx.xi-xu.me/translate&label=Online%20Service)](#-online-service)
 [![Cloudflare Workers](https://img.shields.io/badge/Cloudflare-Workers-orange?logo=cloudflare)](#-self-deployment)

README.zh.md

@@ -1,5 +1,7 @@
 # DeepLX
 
+***[English](README.md)***
+
 [![许可证](https://img.shields.io/github/license/xixu-me/deeplx)](#-许可证)
 [![部署状态](https://img.shields.io/website?url=https://dplx.xi-xu.me/translate&label=在线服务)](#-在线服务)
 [![Cloudflare Workers](https://img.shields.io/badge/Cloudflare-Workers-orange?logo=cloudflare)](#-自部署)