chore: move pr template into github (#119)

Author: ferhatelmas

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,9 @@
+# Submit a pull request
+
+## CLA
+
+- [ ] I have signed the [Stream CLA](https://docs.google.com/forms/d/e/1FAIpQLScFKsKkAJI7mhCr7K9rEIOpqIDThrWxuvxnwUq2XkHyG154vQ/viewform) (required).
+- [ ] The code changes follow best practices
+- [ ] Code changes are tested (add some information if not applicable)
+
+## Description of the pull request