Use automatic links for full changelog in the release drafter template (#3030)

Author: seisman

.github/release-drafter.yml

@@ -53,7 +53,7 @@ template: |
 
   $CHANGES
 
-  **Full Changelog**: https://github.com/$OWNER/$REPOSITORY/compare/$PREVIOUS_TAG...v$RESOLVED_VERSION
+  **Full Changelog**: <https://github.com/$OWNER/$REPOSITORY/compare/$PREVIOUS_TAG...v$RESOLVED_VERSION>
 
   ### Contributors