Update README.md

Author: ByteDecoder

README.md

@@ -3,6 +3,7 @@
 ![.NET Core](https://github.com/ByteDecoder/RoyalLibrary/workflows/.NET%20Core/badge.svg?branch=master)
 [![Maintainability](https://api.codeclimate.com/v1/badges/7e3f41ebb34cf31f1d82/maintainability)](https://codeclimate.com/github/ByteDecoder/RoyalLibrary/maintainability)
 [![Test Coverage](https://api.codeclimate.com/v1/badges/7e3f41ebb34cf31f1d82/test_coverage)](https://codeclimate.com/github/ByteDecoder/RoyalLibrary/test_coverage)
+![CodeQL](https://github.com/ByteDecoder/RoyalLibrary/workflows/CodeQL/badge.svg)
 ![License](https://img.shields.io/badge/license-MIT-green)
 
 Collection of useful LINQ query operators