Add sum function to readme
@ -84,6 +84,7 @@ The function output is dictated by the function itself.
| avg() | Provides the average value of an array of numbers | Double |
| stddev() | Provides the standard deviation value of an array of numbers | Double |
| length() | Provides the length of an array | Integer |
| sum() | Provides the sum value of an array of numbers | Double |
Filter Operators