Improve guidance when confirmation token expired

Previously when a User attempted to use an expired Devise confirmation
token, the error message instructed them to request a new token without
explaining how to do it. The message is only displayed on the page for
requesting a new token, but the User must infer that by the context,
which was confusing to some users. This simply adds the word "below" so
Users do not need to infer - they can follow the written instruction.

config/locales/devise.en.yml

@@ -53,7 +53,7 @@ en:
   errors:
     messages:
       already_confirmed: "was already confirmed, please try signing in"
-      confirmation_period_expired: "needs to be confirmed within %{period}, please request a new one"
+      confirmation_period_expired: "needs to be confirmed within %{period}, please request a new one below"
       expired: "has expired, please request a new one"
       not_found: "not found"
       not_locked: "was not locked"