AI policy (#2405)

This is pretty short. I don't think vibe coders read this anyway so it
won't stop that problem but it should give more free reign to close
things.

Reviewers are volunteers so you can pick what to review. If you don't
want to review something that was 25% written by Claude or whatever else
then you're welcome to just not review it. As always.

---------

Co-authored-by: Brackets-Coder <[email protected]>

Author: GarboMuffin

CONTRIBUTING.md

@@ -10,6 +10,15 @@ To learn how to write custom extensions, see our documentation:
 
 The rest of this page is about this specific repository.
 
+## AI policy
+
+Like any tool, AI has good uses and bad uses. Follow these guidelines to avoid wasting your time and ours:
+
+ - **No AI-generated images under any condition**. We would rather not have an image than use AI slop. Many humans have very finely tuned slop detectors. They won't be happy when they notice.
+ - **Be transparent about what AI tools you used and to what extent**. There's a lot of ways to tell if code was written with AI, so there's no reason to lie.
+ - **Don't submit code that is entirely AI-generated**. There must be a human involved in reviewing and testing all changes. Even if you didn't write the code, it's under your name. If you can't understand your own code, we have no hope of understanding either.
+ - **Reviewers are volunteers**. They are free to weigh your usage of AI in deciding whether or when to review your change.
+
 ## Acceptance criteria
 
 These categories of extensions are **highly discouraged**: