readme change

Author: Schwaneberg

README.md

@@ -41,7 +41,7 @@ Grafana can be used to easily create [Dashboards](https://snapshot.raintank.io/d
 
 ### Reccommendations
 * To prevent queuing of multiple reads configure sample caching with the `cache_interval` option.
-* If a meter supplies an energy consumption counter and a power measurement the power measurement can be discarded.
+* If a meter supplies an energy consumption counter and a power measurement, the power measurement can be discarded.
   The power measurement average can instead be calculated from the difference between energy consumption datapoints.
 
 ### Prometheus Configuration Example