ci: add newlines [skip ci]

Author: peaceiris

.github/label-commenter-config.yml

@@ -1,11 +1,9 @@
 comment:
   header: Hi, there.
   footer: "\
-    ---
-
+    ---\n\n
     > This is an automated comment created by the [peaceiris/actions-label-commenter]. \
-    Responding to the bot or mentioning it won't have any effect.
-
+    Responding to the bot or mentioning it won't have any effect.\n\n
     [peaceiris/actions-label-commenter]: https://github.com/peaceiris/actions-label-commenter
     "