update doc

Author: alexcheng1982

README.md

@@ -1,5 +1,8 @@
 # Easy LLM Tools
 
+[![build](https://github.com/JavaAIDev/easy-llm-tools/actions/workflows/build.yaml/badge.svg)](https://github.com/JavaAIDev/easy-llm-tools/actions/workflows/build.yaml)
+![Maven Central Version](https://img.shields.io/maven-central/v/com.javaaidev.easyllmtools/llm-tool-spec)
+
 Build LLM Tools Easily
 
 See [doc](https://javaaidev.com/docs/easy-llm-tools/intro/)