Merge pull request #7577 from hercules-ci/pr-template

.github: Add pull request template

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,28 @@
+# Motivation
+<!-- Briefly explain what the change is about and why it is desirable. -->
+
+# Context
+<!-- Provide context. Reference open issues if available. -->
+
+<!-- Non-trivial change: Briefly outline the implementation strategy. -->
+
+<!-- Invasive change: Discuss alternative designs or approaches you considered. -->
+
+<!-- Large change: Provide instructions to reviewers how to read the diff. -->
+
+# Checklist for maintainers
+
+<!-- Contributors: please leave this as is -->
+
+Maintainers: tick if completed or explain if not relevant
+
+ - [ ] agreed on idea
+ - [ ] agreed on implementation strategy
+ - [ ] tests, as appropriate
+   - functional tests - `tests/**.sh`
+   - unit tests - `src/*/tests`
+   - integration tests
+ - [ ] documentation in the manual
+ - [ ] code and comments are self-explanatory
+ - [ ] commit message explains why the change was made
+ - [ ] new feature or bug fix: updated release notes