chore: update PR template to add description of generative AI tools (#183)

Author: zjw1111

.github/PULL_REQUEST_TEMPLATE.md

@@ -18,3 +18,12 @@ Linked issue: close #xxx
 ### Documentation
 
 <!-- Does this change introduce a new feature -->
+
+### Generative AI tooling
+
+<!--
+If generative AI tooling has been used in the process of authoring this patch, please include the
+phrase: 'Generated-by: ' followed by the name of the tool and its version.
+If no, write 'No'.
+Please refer to the [ASF Generative Tooling Guidance](https://www.apache.org/legal/generative-tooling.html) for details.
+-->