add PR template

Author: lmcorbalan

.github/pull_request_template.md

@@ -0,0 +1,33 @@
+### Description
+
+<!--
+What's included in this PR?
+-->
+
+### Drive-by changes
+
+<!--
+Are there any minor or drive-by changes also included?
+-->
+
+### Related issues
+
+<!--
+- Fixes #[issue number here]
+-->
+
+### Backward compatibility
+
+<!--
+Are these changes backward compatible? Are there any infrastructure implications, e.g. changes that would prohibit deploying older commits using this infra tooling?
+
+Yes/No
+-->
+
+### Testing
+
+<!--
+What kind of testing have these changes undergone?
+
+None/Manual/Unit Tests
+-->