Add release_body_url sample

Author: luongvo

.github/workflows/create_release_pr.yml

@@ -29,4 +29,5 @@ jobs:
         with:
           release_version: ${{ steps.version.outputs.templateScriptVersion }}
           changelog_configuration: ".github/workflows/config/changelog-release.json"
+          release_body_url: "https://github.com/luongvo/flutter-survey/milestone/9"
           assignee: luongvo-bot