feat(docs): add test actions badge

Author: edorgeville

README.md

@@ -1,7 +1,8 @@
 <div align="center">
   <img src="assets/trpc-mqtt-readme.png" alt="trpc-mqtt" />
   <h1>trpc-mqtt</h1>
-  <a href="https://www.npmjs.com/package/trpc-mqtt"><img src="https://img.shields.io/npm/v/trpc-mqtt.svg?style=flat&color=brightgreen" target="_blank" /></a>
+  <a href="https://www.npmjs.com/package/trpc-mqtt"><img src="https://img.shields.io/npm/v/trpc-mqtt.svg?style=flat&color=brightgreen" /></a>
+  <a href="https://github.com/edorgeville/trpc-mqtt/actions/workflows/test.yml"><img src="https://github.com/edorgeville/trpc-mqtt/actions/workflows/test.yml/badge.svg" /></a>
   <a href="./LICENSE"><img src="https://img.shields.io/badge/license-MIT-black" /></a>
   <br />
   <hr />