Add stable array sort to the arrays group (#1147)

Author: foolip

features/stable-array-sort.yml

@@ -1,6 +1,7 @@
 name: Stable array sort
 description: Stable array sort() function
 spec: https://tc39.es/ecma262/multipage/indexed-collections.html#sec-array.prototype.sort
+group: arrays
 snapshot: ecmascript-2019
 status:
   baseline: high