docs(README): add some badge
# NanoMQ
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[![The best IoT MQTT open source team looks forward to your joining](https://www.emqx.io/static/img/github_readme_en_bg.png)](https://www.emqx.io/careers)NanoMQ MQTT Broker (NanoMQ) is a lightweight and blazing-fast MQTT Broker for the IoT Edge platform.
NanoMQ bases on NNG's asynchronous I/O threading model, with an extension of MQTT support in the protocol layer and reworked transport layer. Plus, an enhanced asynchronous IO mechanism to maximize the overall capacity.
