Fix typo

examples/vars.yml

@@ -14,7 +14,7 @@ matrix_domain: YOUR_BARE_DOMAIN_NAME_HERE
 #
 # In case SSL renewal fails at some point, you'll also get an email notification there.
 #
-# If you decide to use another method for managing SSL certifites (different than the default Let's Encrypt),
+# If you decide to use another method for managing SSL certificates (different than the default Let's Encrypt),
 # you won't be required to define this variable (see `docs/configuring-playbook-ssl-certificates.md`).
 #
 # Example value: someone@example.com