Update Pull Request Template (#376)

.github/pull_request_template.md

@@ -1,17 +1,25 @@
-<!--
-Thanks for submitting a PR, your contribution is really appreciated!
-Below are a few things we ask you kindly to self-check before getting a review. Remove checks that are not relevant.
+<!-- Thanks for submitting a PR, your contribution is really appreciated! -->
+<!-- Unless your change is trivial, please create an issue to discuss the change before creating a PR -->
+<!-- Below are a few things we ask you kindly to self-check before getting a review. Remove checks that are not relevant.
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-Checklist
+## Change Summary
+
+<!-- Please give a short summary of the changes. -->
 
-- [ ] Passes `pre-commit run --all-files`
-- [ ] Tests added / passed
+## Related issue number
 
+<!-- Are there any issues opened that will be resolved by merging this change? -->
 <!--
 Please note any issues this fixes using [closing keywords]( https://help.github.com/articles/closing-issues-using-keywords/ ):
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+## Checklist
+
+- [ ] Unit tests for the changes exist
+- [ ] Tests pass on CI
+- [ ] Documentation reflects the changes where applicable
+
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