update doc

Author: alexcheng1982

README.md

@@ -17,7 +17,7 @@ Add Maven dependency.
 <dependency>
   <groupId>com.javaaidev</groupId>
   <artifactId>springai-openai-client</artifactId>
-  <version>0.7.0</version>
+  <version>0.8.0</version>
 </dependency>
 ```