added 30 year normals

README.md

@@ -11,6 +11,7 @@ The data in mongodb has the following fields:
 * ```year``` - Year of the data
 * ```min_temps``` - Minimum daily temperature as an array. One element is one day
 * ```max_temps``` - Maximum daily temperature as an array. One element is one day
+* ```normal``` - Indicates whether the data is a 30 year normal or not
 
 #### API Endpoints
 * ```POST /api/:product/:year```