Update pull_request_template.md

Co-authored-by: Jade <[email protected]>

.github/pull_request_template.md

@@ -4,6 +4,8 @@ What changed? Why? (the code + comments should speak for itself on the "how")
 
 Fun screenshots ir a cool video or something are super helpful as well. If this touches platform-specific behavior, this is where test evidence should be collected.
 
+Any issues this pull request closes or pull requests this supersedes should be linked with `Closes #issuenumber`.
+
 ## Meta
 
 Merge checklist: