Update 'README.md'

README.md

@@ -1,3 +1,42 @@
 # dart_openai
 
-openai sdk
+openai sdk
+
+## Usage
+
+```
+  dart_openai: ^1.9.1
+  
+  
+```
+
+
+
+## Reference
+
+类似项目：
+
+- [chat_gpt_sdk](https://pub.dev/packages/chat_gpt_sdk)
+
+```
+_openAI = OpenAI.instance.build(
+            token: OPENAI_API_KEY,
+            baseOption: HttpSetup(receiveTimeout: const Duration(seconds: 5)),
+            enableLog: true);
+            
+
+final request = ChatCompleteText(
+    model: GptTurbo0301ChatModel(),
+    messages: messagesHistory,
+    maxToken: 200);
+
+final response = await _openAI.onChatCompletion(request: request);
+
+return response!.choices
+    .map((choice) => ChatMessage(
+        user: ChatUser(id: '2'),
+        createdAt: DateTime.now(),
+        text: choice.message!.content))
+    .toList();
+}
+```