Add pull request template with checklist

Author: Volodumur-Yatsenko

.github/pull_request_template.md

@@ -0,0 +1,5 @@
+## Checklist before requesting a review
+- [ ] I have performed a self-review of my code
+- [ ] If it is a core feature, I have added thorough tests
+- [ ] Do we need to implement analytics?
+- [ ] Will this be part of a product update? If yes, please write one phrase about this update