rawmoment: cleaning

Author: jvdp1

src/stdlib_experimental_stats.md

@@ -75,7 +75,7 @@ The _k_-th order central moment is defined as :
 
 `result = moment(array, order [, center [, mask]])`
 
-`result = moment(array, order, ,dim [, center [, mask]])`
+`result = moment(array, order, dim [, center [, mask]])`
 
 ### Arguments