Merge pull request #554 from jonathanvila/add-sum-function-to-readme

Add sum function to readme

Author: kallestenflo

README.md

@@ -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