doc: add Aqua badge to README.md

Author: franckgaga

README.md

@@ -2,6 +2,7 @@
 
 [![Build Status](https://github.com/JuliaControl/ModelPredictiveControl.jl/actions/workflows/CI.yml/badge.svg?branch=main)](https://github.com/JuliaControl/ModelPredictiveControl.jl/actions/workflows/CI.yml?query=branch%3Amain)
 [![codecov](https://codecov.io/gh/JuliaControl/ModelPredictiveControl.jl/branch/main/graph/badge.svg?token=K4V0L113M4)](https://codecov.io/gh/JuliaControl/ModelPredictiveControl.jl)
+[![Aqua QA](https://juliatesting.github.io/Aqua.jl/dev/assets/badge.svg)](https://github.com/JuliaTesting/Aqua.jl)
 [![doc-stable](https://img.shields.io/badge/docs-stable-blue.svg)](https://JuliaControl.github.io/ModelPredictiveControl.jl/stable)
 [![doc-dev](https://img.shields.io/badge/docs-dev-blue.svg)](https://JuliaControl.github.io/ModelPredictiveControl.jl/dev)
 [![arXiv](https://img.shields.io/badge/arXiv-2411.09764-b31b1b.svg)](https://arxiv.org/abs/2411.09764)