README 에 CI 배지 추가

Author: code-yeongyu

README.md

@@ -3,7 +3,7 @@
   <h1 align="center">TrackPurchase</h1>
 </p>
 
-[![NPM version](https://badgen.net/npm/v/trackpurchase)](https://www.npmjs.com/package/trackpurchase) [![codecov](https://codecov.io/gh/code-yeongyu/TrackPurchase/branch/master/graph/badge.svg?token=UCZC198HMK)](https://codecov.io/gh/code-yeongyu/TrackPurchase)
+[![NPM version](https://badgen.net/npm/v/trackpurchase)](https://www.npmjs.com/package/trackpurchase) [![codecov](https://codecov.io/gh/code-yeongyu/TrackPurchase/branch/master/graph/badge.svg?token=UCZC198HMK)](https://codecov.io/gh/code-yeongyu/TrackPurchase) [![CI](https://github.com/code-yeongyu/TrackPurchase/actions/workflows/ci.yml/badge.svg)](https://github.com/code-yeongyu/TrackPurchase/actions/workflows/ci.yml)
 
 > 단 몇줄만의 코드로 다양한 쇼핑 플랫폼에서 결제 내역을 긁어오자!