README.md in fluent-plugin-cloudwatch-1.1.0 vs README.md in fluent-plugin-cloudwatch-1.2.0

@@ -24,9 +24,10 @@
   statistics       [statistics] (default: Average)
   metric_name      [metric name]
   dimensions_name  [dimensions_name]
   dimensions_value [dimensions value]
   period           [period] (default: 60)
+  interval         [interval] (default: 60)
 </source>
 
 ```
 
 ### GET RDS Metric