Get rid of platform differences in Grouping<T, K>.eachCount() doc

libraries/stdlib/js/src/kotlin/grouping.kt

@@ -7,7 +7,9 @@ package kotlin.collections
 /**
  * Groups elements from the [Grouping] source by key and counts elements in each group.
  *
- * @return a [Map] associating the key of each group with the count of element in the group.
+ * @return a [Map] associating the key of each group with the count of elements in the group.
+ *
+ * @sample samples.collections.Grouping.groupingByEachCount
  */
 @SinceKotlin("1.1")
 public actual fun <T, K> Grouping<T, K>.eachCount(): Map<K, Int> =