chore: Move PR template

Author: Jasenkoo

.github/PULL_REQUEST_TEMPLATE/pull_request_template.md renamed to .github/pull_request_template.md

@@ -4,5 +4,5 @@
 
 ## Checklist before requesting a review
 - [ ] I have performed a self-review of my code
-- [ ] I have ensured that unit test pass without errors
+- [ ] I have ensured that unit tests pass without errors
 - [ ] If it is a new feature, I have added a new unit test