chore(PULL_REQUEST_TEMPLATE): add new section

Author: philippschulte

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,3 +1,11 @@
+### Change summary
+
+ <!--
+Briefly describe the changes introduced in this pull request. Include context or
+reasoning behind the changes, even if they seem minor. If relevant, link to any
+related discussions (e.g. Slack threads, tickets, documents).
+-->
+
  All Submissions:
 
 * [ ] Have you followed the guidelines in our Contributing document?
@@ -11,7 +19,6 @@
 
 ### Changes to Core Features:
 
-* [ ] Have you added an explanation of what your changes do and why you'd like us to include them?
 * [ ] Have you written new tests for your core changes, as applicable?
 * [ ] Have you successfully run tests with your changes locally?
 
@@ -21,4 +28,4 @@
 
 ### Are there any considerations that need to be addressed for release?
 
-<!-- Any breaking changes, etc -->
+<!-- Any breaking changes, etc -->