examples: Update openai chat example

examples/openai-chat-example/openai_chat_example.go

@@ -11,22 +11,33 @@ import (
 )
 
 func main() {
-	llm, err := openai.NewChat()
+	llm, err := openai.New()
 	if err != nil {
 		log.Fatal(err)
 	}
 	ctx := context.Background()
-	completion, err := llm.Call(ctx, []schema.ChatMessage{
-		schema.SystemChatMessage{Content: "Hello, I am a friendly chatbot. I love to talk about movies, books and music. Answer in long form yaml."},
-		schema.HumanChatMessage{Content: "What would be a good company name a company that makes colorful socks?"},
+	_, err = llm.GenerateContent(ctx, []llms.MessageContent{
+		{
+			Role: schema.ChatMessageTypeSystem,
+			Parts: []llms.ContentPart{
+				llms.TextContent{
+					Text: "Hello, I am a friendly chatbot. I love to talk about movies, books and music. Answer in long form yaml.",
+				},
+			},
+		},
+		{
+			Role: schema.ChatMessageTypeHuman,
+			Parts: []llms.ContentPart{
+				llms.TextContent{
+					Text: "What would be a good company name a company that makes colorful socks?",
+				},
+			},
+		},
 	}, llms.WithStreamingFunc(func(ctx context.Context, chunk []byte) error {
 		fmt.Print(string(chunk))
 		return nil
-	}),
-	)
+	}))
 	if err != nil {
 		log.Fatal(err)
 	}
-
-	fmt.Println(completion)
 }