add badge Maintainability

Author: root

README.md

@@ -1,2 +1,3 @@
 ### Hexlet tests and linter status:
-[![Actions Status](https://github.com/aptart/frontend-project-44/actions/workflows/hexlet-check.yml/badge.svg)](https://github.com/aptart/frontend-project-44/actions)
+[![Actions Status](https://github.com/aptart/frontend-project-44/actions/workflows/hexlet-check.yml/badge.svg)](https://github.com/aptart/frontend-project-44/actions)
+<a href="https://codeclimate.com/github/aptart/frontend-project-44/maintainability"><img src="https://api.codeclimate.com/v1/badges/97d0f050464bd5679e47/maintainability" /></a>