MC-20549: Refactor CE modules E-mail templates to use scalars variables

- Fix email template typo

Author: Hwashiang Yu

app/design/frontend/Magento/luma/Magento_Email/email/footer.html

@@ -8,7 +8,7 @@
 <!--@vars {
 "var store.frontend_name":"Store Name",
 "var url_about_us":"About Us URL",
-"var url_customer_service":"Customer Server URL",
+"var url_customer_service":"Customer Service URL",
 "var store_phone":"Store Phone",
 "var store_hours":"Store Hours",
 "var store.formatted_address|raw":"Store Address"