github: make "resolves" in PR template a list to display issue titles

Signed-off-by: Yury V. Zaytsev <[email protected]>

Author: zyv

.github/PULL_REQUEST_TEMPLATE.md

@@ -6,7 +6,7 @@
 Describe the big picture of your changes here, to communicate to the maintainers why we should accept this pull request. If it fixes a bug or resolves a feature request, be sure to link to that issue.
 -->
 
-Resolves: #...
+* Resolves: #...
 
 ## Checklist