update ChatModelInput example

Author: Barqawiz

README.md

@@ -114,8 +114,7 @@ Chatbot bot = new Chatbot(apiKey, SupportedChatModels.openai);
 // 2- prepare the chat history by calling addMessage.
 String mode = "You are a helpful astronomy assistant.";
 ChatModelInput input = new ChatGPTInput.Builder(mode)
-								.addUserMessage("what is the space between moon and earth")
-								.build();
+                       .addUserMessage("what is the space between moon and earth").build();
 
 // 3- call chat!
 List<String> resValues =  bot.chat(input);