chore: add prefixed with "#" for issue number

Author: trivikr

.github/pull_request_template.md

@@ -1,5 +1,5 @@
 ### Issue
-Issue number, if available
+Issue number, if available, prefixed with "#"
 
 ### Description
 What does this implement/fix? Explain your changes.
@@ -11,4 +11,4 @@ How was this change tested?
 Add any other context about the PR here.
 
 ---
-By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.
+By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.