Update README.md

README.md

@@ -10,6 +10,7 @@
 [![Build status](https://ci.appveyor.com/api/projects/status/ngpppvnnfu8ehjw3/branch/develop?svg=true)](https://ci.appveyor.com/project/eXistdbci/exist/branch/develop)
 [![Coverage Status](https://coveralls.io/repos/github/eXist-db/exist/badge.svg?branch=develop)](https://coveralls.io/github/eXist-db/exist?branch=develop)
 [![Codacy Badge](https://app.codacy.com/project/badge/Grade/ae1c8a7eb1164e919b0ac3c8588560c6)](https://www.codacy.com/gh/eXist-db/exist/dashboard?utm_source=github.com&utm_medium=referral&utm_content=eXist-db/exist&utm_campaign=Badge_Grade)
+[![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=eXist-db_exist&metric=alert_status)](https://sonarcloud.io/summary/new_code?id=eXist-db_exist)
 [![Java 8](https://img.shields.io/badge/java-8-blue.svg)](https://adoptopenjdk.net/)
 [![License](https://img.shields.io/badge/license-LGPL%202.1-blue.svg)](https://www.gnu.org/licenses/lgpl-2.1.html)
 [![Download](https://img.shields.io/github/v/release/eXist-db/exist.svg)](https://github.com/eXist-db/exist/releases/)