Update README.md

Author: ocots

README.md

@@ -107,6 +107,9 @@ You can find first good issues (if any 🙂) [here][first-good-issue-url]. You m
 
 If you want to ask a question, feel free to start a discussion [here](https://github.com/orgs/control-toolbox/discussions). This forum is for general discussion about this repository and the [control-toolbox organization](https://github.com/control-toolbox).
 
+>[!NOTE]
+> If you want to add an application or a package to the control-toolbox ecosystem, please follow this [set up tutorial](https://github.com/control-toolbox/CTApp.jl/discussions/9).
+
 ## See also
 
-We acknowledge support of colleagues from [ADNLPModels](https://jso.dev/ADNLPModels.jl/stable) @[Julia Smooth Optimizers](https://jso.dev).
+We acknowledge support of colleagues from [ADNLPModels](https://jso.dev/ADNLPModels.jl/stable) @[Julia Smooth Optimizers](https://jso.dev) and [MadNLP](github.com/MadNLP/MadNLP.jl).