Update README.md

README.md

@@ -5,6 +5,7 @@
 
 <p align="center">
    <a href="https://scan.coverity.com/projects/pit-ray-fluent-tray"><img alt="Coverity Scan Build Status" src="https://img.shields.io/coverity/scan/pit-ray-fluent-tray?style=flat-square" /></a>
+   <a href="https://coveralls.io/github/pit-ray/fluent-tray"><img alt="Coveralls" src="https://img.shields.io/coverallsCoverage/github/pit-ray/fluent-tray?style=flat-square"></a>
     <a href="https://www.codacy.com/gh/pit-ray/fluent-tray/dashboard?utm_source=github.com&amp;utm_medium=referral&amp;utm_content=pit-ray/fluent-tray&amp;utm_campaign=Badge_Grade"><img src="https://img.shields.io/codacy/grade/8f2e6f2826904efd82019f5888574327?style=flat-square" /></a>
   <a href="https://github.com/pit-ray/fluent-tray/actions/workflows/codeql.yml"><img src="https://img.shields.io/github/actions/workflow/status/pit-ray/fluent-tray/codeql.yml?branch=main&label=CodeQL&logo=github&style=flat-square"/></a>
   <br>