CONTRIBUTION.md: some sentences about LLM

.github/PULL_REQUEST_TEMPLATE.md

@@ -24,6 +24,21 @@
 - the expected success test output
 -->
 
+### Declaration of [Generative AI]-Tool-usage:
+> [!NOTE]
+> Please delete the sentences and parts of them  that are untrue.
+> Please add information (e.g., name tools or technologies) if needed.
+- A LLM agent generated this entire PR either on behave of a human or selftriggered.
+- A LLM was used to produce whole file(s), function(s), codeblocks or snippets.
+- A LLM was used to produce documentation.
+- A LLM was used to check the code.
+- another kind of [Generative AI]-Tool was used to do something. 
+- No [Generative AI]-Tool was used in any way but spellcheck
+
+Tools that were used are:
+none
+
+[Generative AI]: https://en.wikipedia.org/wiki/Generative_artificial_intelligence
 
 ### Issues/PRs references
 

CONTRIBUTING.md

@@ -208,6 +208,26 @@ into the source repository.
 [archived-pull-requests]: https://github.com/RIOT-OS/RIOT/pulls?q=is:pr+label:"State:+archived"
 [uncrustify]: http://uncrustify.sourceforge.net
 
+## Plagiarism and AI
+
+RIOT itself applies the LGPL license, see [LICENSE.md], to most of its code exclusively,
+authors of PRs are assumed to do so as well (not necessary exclusive).
+When a PR is published it must also respect all authorship-rights, copyrights and
+licenses of code it uses. If code is copied the original author usually must be named and
+the original license must be kept, unless the original license states differently.
+[Generative AI] (e.g., Large language models (LLM)) are known to sometimes reproduce
+large amounts of content (code), that was fed into their database as such it might
+produce a copy and the previous sentence must be applied.
+When reworking a PR and copying its code to a new one, the author of that original reproduced
+code still is the original author and their rights to the code must be respected
+such as naming them and keeping the license.
+
+If a PR was written using tooling that is able to reproduce code from a knowlege-base, e.g.,
+large language model assisted tools like Copilot, Devin AI or Cursor or LLMs like GPT and Ollama,
+the PR should be marked as such and describe to what extent the tool was used
+(producing whole files, functions, code blocks, documentation, code/spell checking).
+[Generative AI]: https://en.wikipedia.org/wiki/Generative_artificial_intelligence
+
 ## Writing Documentation
 [writing-documentation]: #writing-documentation