ci: add PR template

Author: jszutenb

pull_request_template.md

@@ -0,0 +1,20 @@
+## Description
+
+The summary of the proposed changes as long as the relevant motivation and context.
+
+## Issues
+
+Fixes #(github issue). If there is no such issue, please mark it as `n/a`.
+
+## Type of change
+
+List the type of change like below. Please delete options that are not relevant.
+
+- [ ] Bug fix (non-breaking change which fixes an issue)
+- [ ] New feature (non-breaking change which adds new functionality)
+- [ ] Breaking change (fix or feature that would break existing design and interface)
+- [ ] Others (enhancement, documentation, validation, etc.)
+
+## Tests
+
+Describe the tests that you ran to verify your changes.