chg: [doc] contribution added

README.md

@@ -182,5 +182,9 @@ cpe (vendor:product) per version to give a probability of the CPE appearance.
 
 Software is open source and released under a 2-Clause BSD License
 
-Copyright (C) 2021-2024 Alexandre Dulaunoy
-Copyright (C) 2021-2024 Esa Jokinen
+~~~
+  Copyright (C) 2021-2024 Alexandre Dulaunoy
+  Copyright (C) 2021-2024 Esa Jokinen
+~~~
+
+We welcome contributions! All contributors collectively own the CPE Guesser project. By contributing, contributors also acknowledge the [Developer Certificate of Origin](https://developercertificate.org/) when submitting pull requests or using other methods of contribution.