Add AI guidelines and requirements.

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,4 +1,11 @@
- <!-- Filling this template is mandatory -->
+#
+# IT IS NOT ALLOWED TO GENERATE THE PR DESCRIPTION WITH AI!
+#
+# See CONTRIBUTING.md for our AI guidelines.
+#
+
+
+<!-- Filling this template is mandatory -->
 
 **Your checklist for this pull request**
 - [ ] I've documented or updated the documentation of every API function and struct this PR changes.

CONTRIBUTING.md

@@ -83,6 +83,26 @@ Coding style
 - We provide a `.clang-format` for C code.
 - Python files should be formatted with `black`.
 
+AI guidelines
+------------
+Using AI for contributions is generally allowed (see exception below).
+Please be aware that everything has to be tested thoroughly.
+The larger the PR, the more rigid our requirements are.
+
+> [!NOTE]
+> We highly recommend limiting AI usage to small or repetitive changes.
+> The rule of thumb is:
+>
+> _If you spent an annoying amount of time checking the code, your task is not suitable for AI._
+
+> [!IMPORTANT]
+> It is forbidden to let AI write the PR description!
+> If **you** can't explain what the change does, AI was not the right tool.
+
+Translations with AI are, of course, allowed.
+If you use it, please write simple, short sentences in your native language
+so the AI doesn't translate them too floridly.
+
 Support
 -------