Update README.md

Author: aleksandr-pronichev

README.md

@@ -1,2 +1,3 @@
 ### Hexlet tests and linter status:
-[![Actions Status](https://github.com/aleksandr-pronichev/java-project-61/actions/workflows/hexlet-check.yml/badge.svg)](https://github.com/aleksandr-pronichev/java-project-61/actions)
+[![Actions Status](https://github.com/aleksandr-pronichev/java-project-61/actions/workflows/hexlet-check.yml/badge.svg)](https://github.com/aleksandr-pronichev/java-project-61/actions)
+[![Maintainability](https://api.codeclimate.com/v1/badges/71de738da0be378eb55e/maintainability)](https://codeclimate.com/github/aleksandr-pronichev/java-project-61/maintainability)