Fix typo

examples/vars.yml

@@ -28,7 +28,7 @@ matrix_coturn_turn_static_auth_secret: ''
 # You can put any string here, but generating a strong one is preferred (e.g. `pwgen -s 64 1`).
 matrix_synapse_macaroon_secret_key: ''
 
-# A Postgres password to used for the superuser Postgres user (called `matrix` by default).
+# A Postgres password to use for the superuser Postgres user (called `matrix` by default).
 #
 # The playbook creates additional Postgres users and databases (one for each enabled service)
 # using this superuser account.