emphasize the timestamp

.github/workflows/spelling-check-bot.yml

@@ -43,7 +43,7 @@ jobs:
           > To exclude words from the spellchecker, you can add valid words (web technology terms or abbreviations) to the [terms-abbreviations.txt](https://github.com/mdn/content/blob/main/.vscode/terms-abbreviations.txt) dictionary for IDE autocompletion. To ignore strings that are not words (\`AABBCC\` in code, for instance), you can add them to [ignore-list.txt](https://github.com/mdn/content/blob/main/.vscode/ignore-list.txt).
           EOM
           )
-          comment_body+=$'\n\n'$(echo "(comment last updated: $(date +'%Y-%m-%d %H:%M:%S'))")
+          comment_body+=$'\n\n'$(echo "_(comment last updated: $(date +'%Y-%m-%d %H:%M:%S'))_")
           gh api \
             --method PATCH \
             -H "Accept: application/vnd.github+json" \