Readme: Add Telegram link

README_en.md

@@ -2,6 +2,8 @@
 
 ## Introduction
 
+[![Telegram](https://img.shields.io/badge/Telegram-2CA5E0?style=for-the-badge&logo=telegram&logoColor=white "langchain-chatglm")](https://t.me/+RjliQ3jnJ1YyN2E9)
+
 🌍 [_中文文档_](README.md)
 
 🤖️ This is a ChatGLM application based on local knowledge, implemented using [ChatGLM-6B](https://github.com/THUDM/ChatGLM-6B) and [langchain](https://github.com/hwchase17/langchain).
@@ -205,4 +207,4 @@ ChatGLM's answer after using LangChain to access the README.md file of the ChatG
    - [ ] Add output and error messages
    - [ ] Internationalization for language switching
    - [ ] Citation callout
-- [ ] Use FastAPI to implement API deployment method and develop a Web UI DEMO for API calls
\ No newline at end of file
+- [ ] Use FastAPI to implement API deployment method and develop a Web UI DEMO for API calls