Create pull_request_template.md

Author: labkey-klum

pull_request_template.md

@@ -0,0 +1,8 @@
+#### Rationale
+<!-- Rationale describing why this pull request is needed, what behavior it's adding/changing/removing, etc. (replace this comment) -->
+
+#### Related Pull Requests
+* <!-- list of links to related pull requests (replace this comment) -->
+
+#### Changes
+* <!-- list of descriptions of changes that are worth noting (replace this comment) -->