Update README.md

Author: javadev

README.md

@@ -1,6 +1,8 @@
 # LeetCode-in-Ruby
 
+[![MIT License](https://img.shields.io/badge/license-MIT-green.svg)](https://github.com/LeetCode-in-Ruby/LeetCode-in-Ruby/blob/main/LICENSE)
 [![Ruby CI](https://github.com/LeetCode-in-Ruby/LeetCode-in-Ruby/actions/workflows/checks.yml/badge.svg)](https://github.com/LeetCode-in-Ruby/LeetCode-in-Ruby/actions/workflows/checks.yml)
+[![Maintainability Rating](https://sonarcloud.io/api/project_badges/measure?project=LeetCode-in-Ruby_LeetCode-in-Ruby&metric=sqale_rating)](https://sonarcloud.io/summary/new_code?id=LeetCode-in-Ruby_LeetCode-in-Ruby)
 [![](https://img.shields.io/github/stars/LeetCode-in-Ruby/LeetCode-in-Ruby?style=flat-square)](https://github.com/LeetCode-in-Ruby/LeetCode-in-Ruby)
 [![](https://img.shields.io/github/forks/LeetCode-in-Ruby/LeetCode-in-Ruby?style=flat-square)](https://github.com/LeetCode-in-Ruby/LeetCode-in-Ruby/fork)