Add IFTTTHandler to docs

src/Monolog/Handler/IFTTTHandler.php

@@ -16,6 +16,12 @@ use Monolog\Logger;
 /**
  * IFTTTHandler uses cURL to trigger IFTTT Maker actions
  *
+ * Register a secret key and trigger/event name at https://ifttt.com/maker
+ *
+ * value1 will be the channel from monolog's Logger constructor,
+ * value2 will be the level name (ERROR, WARNING, ..)
+ * value3 will be the log record's message
+ *
  * @author Nehal Patel <nehal@nehalpatel.me>
  */
 class IFTTTHandler extends AbstractProcessingHandler