Update pull_request_template.md

Author: jackzhxng

.github/pull_request_template.md

@@ -1,11 +1,11 @@
-### Description
+### Summary
 [PLEASE REMOVE] Describe the goal of this PR and any add any relevant context.
 
 ### Test plan
 [PLEASE REMOVE] How did you test this PR? Please write down any manual commands you used and note down tests that you have written.
 
 ### Issue(s) fixed
-[PLEASE REMOVE] List all issues, separate by newlines, that this PR addresses.
+[PLEASE REMOVE] List all issues fixed (e.g. "closes #ISSUE_NUMBER"), separate by newlines, that this PR addresses.
 
 ### Changelog
 [PLEASE REMOVE] If this PR introduces a fix or feature that should be the upcoming release notes, please add the following line below - `+changelog: <description of feature>`