public static ChatRequestBuilder of(String systemMessage, String userMessage) {
		return new ChatRequestBuilder().systemMessage(systemMessage).userMessage(userMessage);
	}
construct ChatGPT request builder from system and user messages
@param systemMessage system message content
@param userMessage user message content
@return builder
src/main/java/org/mvnsearch/chatgpt/model/completion/chat/ChatRequestBuilder.java