📚 Update README.md

Author: ronisbr

README.md

@@ -4,6 +4,7 @@
 [![codecov](https://codecov.io/gh/JuliaSpace/ReferenceFrameRotations.jl/branch/master/graph/badge.svg)](https://codecov.io/gh/JuliaSpace/ReferenceFrameRotations.jl)
 [![](https://img.shields.io/badge/docs-stable-blue.svg)][docs-stable-url]
 [![](https://img.shields.io/badge/docs-dev-blue.svg)][docs-dev-url]
+[![Code Style: Blue](https://img.shields.io/badge/code%20style-blue-4495d1.svg)](https://github.com/invenia/BlueStyle)
 
 This module contains functions related to the representation of 3D rotations of
 reference frames. It is used on a daily basis on projects at the [Brazilian