meta: add pull request template

.github/pull_request_template.md

@@ -0,0 +1,18 @@
+## Summary
+
+Brief explanation of the proposed changes.
+
+## Basic example
+
+Include a basic example, screenshots, or links.
+
+## Motivation
+
+Why are we doing this? What use cases does it support? What is the expected outcome?
+
+## Checks
+
+- [ ] Read [Create a Pull Request](https://getdoks.org/docs/contributing/how-to-contribute/#create-a-pull-request)
+- [ ] Supports all screen sizes (if relevant)
+- [ ] Supports both light and dark mode (if relevant)
+- [ ] Passes `npm run test`