docs: add CI status to README

Author: nirga

README.md

@@ -27,6 +27,9 @@
    <a href="https://github.com/traceloop/openllmetry-js/blob/main/LICENSE">
     <img src="https://img.shields.io/badge/license-Apache 2.0-blue.svg" alt="OpenLLMetry JS is released under the Apache-2.0 License">
   </a>
+  <a href="https://github.com/traceloop/openllmetry-js/actions/workflows/ci.yml">
+  <img src="https://github.com/traceloop/openllmetry-js/actions/workflows/ci.yml/badge.svg">
+  </a>
   <a href="https://www.ycombinator.com/companies/traceloop"><img src="https://img.shields.io/website?color=%23f26522&down_message=Y%20Combinator&label=Backed&logo=ycombinator&style=flat-square&up_message=Y%20Combinator&url=https%3A%2F%2Fwww.ycombinator.com"></a>
   <a href="https://github.com/traceloop/openllmetry-js/blob/main/CONTRIBUTING.md">
     <img src="https://img.shields.io/badge/PRs-Welcome-brightgreen" alt="PRs welcome!" />