docs: Updated the contribution guidelines and PR template to sound more like AI is allowed but only when disclosed

.github/PULL_REQUEST_TEMPLATE/pull_request_template.md

@@ -1,11 +1,18 @@
-### AI assistance (if any):
-- List tools here and files touched by them
+### Description
+<!-- What problem is this PR solving? -->
+
+### Alternatives Considered (Optional)
+<!-- What alternatives did you consider? Why did you choose this approach? -->
+
+### AI assistance (if any)
+<!-- Required if AI assistance was used to write or modify code in this PR. -->
+<!-- - List tools here -->
 
 ### Authorship & Understanding
 
-- [ ] I wrote or heavily modified this code myself
+- [ ] I wrote or heavily modified this code myself. If I didn't, I gave proper attribution to AI assistance above.
 - [ ] I understand how it works end-to-end
 - [ ] I can maintain this code in the future
 - [ ] No undisclosed AI-generated code was used
-- [ ] If AI assistance was used, it is documented below
+- [ ] If AI assistance was used, it is documented above