Add comprehensive PR template from OpenHands repository

.github/pull_request_template.md

@@ -1,4 +1,46 @@
-- [ ] I have read and reviewed the documentation changes to the best of my ability.
-- [ ] If the change is significant, I have run the documentation site locally and confirmed it renders as expected.
+<!-- Keep this PR as draft until it is ready for review. -->
 
-**Summary of changes**
+<!-- AI/LLM agents: be concise and specific. Do not check the box below. -->
+
+- [ ] A human has tested these changes.
+- [ ] For significant changes, I have previewed the docs site locally (`mint dev`) and confirmed rendering
+
+---
+
+## Why
+
+<!-- Describe problem, motivation, etc.-->
+
+## Summary
+
+<!-- 1-3 bullets describing what changed. -->
+-
+
+## Issue Number
+<!-- Required if there is a relevant issue to this PR. -->
+
+## How to Test
+
+<!--
+For code changes: Share steps to test your changes.
+For simple documentation fixes (typos, formatting, links): You can skip this or briefly state what you verified.
+-->
+
+## Video/Screenshots
+
+<!--
+For GUI/visual changes: Provide screenshots or video.
+For documentation content: Provide a screenshot of the rendered page if the change affects layout/formatting, or state "N/A - text-only change".
+-->
+
+## Type
+
+- [ ] Bug fix
+- [ ] Feature
+- [ ] Refactor
+- [ ] Breaking change
+- [ ] Docs / chore
+
+## Notes
+
+<!-- Optional: migrations, config changes, rollout concerns, follow-ups, or anything reviewers should know. -->