fix(config) : Clarity smtp debugging config option usage

Requires temporary `loglevel` adjustment "99%" (made up statistic) of the time as currently implemented.

Signed-off-by: Josh <josh.t.richards@gmail.com>

config/config.sample.php

@@ -493,6 +493,8 @@ $CONFIG = [
 
 /**
  * Enable SMTP class debugging.
+ * NOTE: ``loglevel`` will likely need to be adjusted too. See docs: 
+ *   https://docs.nextcloud.com/server/latest/admin_manual/configuration_server/email_configuration.html#enabling-debug-mode
  *
  * Defaults to ``false``
  */