Add section to explain PR

Author: sebromero

pull_request_template.md

@@ -1,6 +1,8 @@
+## What This PR Changes
+- (Please explain here why you created the pull request and specify what it changes)
+
 ## What Needs To Be Reviewed
-- TBD
-- TBD
+- (Please list here what needs to be reviewed and by whom if multiple people are tagged for review)
 
 ## How To Give Feedback
 Please leave your feedback as a [Github review](https://docs.github.com/en/github/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/about-pull-request-reviews).