Add a PR template (#1439)

* Add PR template

* review response

Author: codybraun

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,9 @@
+## What is this change?
+- (List out the changes.)
+- (Link to any relevant Github issues or Slack discussion)
+
+## Considerations for discussion
+- (List out any significant design decisions that were made and why.)
+
+## How to test the changes (if needed)
+- (How should a reviewer test this functionality)