alibaba/spring-cloud-alibaba ? reverse-engineered prompt

Build me a Spring Cloud Alibaba demo project that shows how to put together a small microservices app with service discovery, centralized config, basic traffic protection, and messaging.

I want a simple but realistic setup with a few services, like a gateway or web app, a user service, and an order service, so I can see how they talk to each other. Please wire it up so I can register services, load config from a shared place, add a basic rate limit or fallback rule, and send an event through messaging when an order is created. If it makes sense, include a small distributed transaction example too.

Please make it easy to run locally, with clear README steps, sample configuration, and example endpoints I can try right away. Use the current docs online if you need to, and keep the code clean and beginner friendly so I can understand how Spring Cloud Alibaba is meant to be used.