Merge pull request #3494 from natecook1000/nc-indexset-contains

Fix IndexSet.contains(integersIn:) documentation

Author: natecook1000

stdlib/public/SDK/Foundation/IndexSet.swift

@@ -414,7 +414,7 @@ public struct IndexSet : ReferenceConvertible, Equatable, BidirectionalCollectio
     public func contains(integersIn range: CountableClosedRange<Element>) -> Bool { return self.contains(integersIn: Range(range)) }
 
 
-    /// Returns `true` if `self` contains any of the integers in `indexSet`.
+    /// Returns `true` if `self` contains all of the integers in `indexSet`.
     public func contains(integersIn indexSet: IndexSet) -> Bool {
         return _handle.map { $0.contains(indexSet) }
     }