[BasicContainers] Fix typos in doc comments

Author: lorentey

Sources/BasicContainers/RigidArray/RigidArray+Container.swift

@@ -303,7 +303,7 @@ extension RigidArray where Element: ~Copyable {
   ///    This optimization may be removed in future versions; do not rely on it.
   ///
   /// - Parameter index: A valid index of the array. On return, `index` is
-  ///    set to `limit` if
+  ///    set to the resulting position.
   /// - Parameter n: The distance to offset `index`.
   ///    On return, `n` is set to zero if the operation succeeded without
   ///    hitting the limit; otherwise, `n` reflects the number of steps that

Sources/BasicContainers/UniqueArray/UniqueArray+Container.swift

@@ -264,7 +264,7 @@ extension UniqueArray where Element: ~Copyable {
   ///    This optimization may be removed in future versions; do not rely on it.
   ///
   /// - Parameter index: A valid index of the array. On return, `index` is
-  ///    set to `limit` if
+  ///    set to the resulting position.
   /// - Parameter n: The distance to offset `index`.
   ///    On return, `n` is set to zero if the operation succeeded without
   ///    hitting the limit; otherwise, `n` reflects the number of steps that

Sources/BasicContainers/UniqueArray/UniqueArray+Insertions.swift

@@ -281,7 +281,7 @@ extension UniqueArray where Element: ~Copyable {
 
 @available(SwiftStdlib 5.0, *)
 extension UniqueArray {
-  /// Copyies the elements of a fully initialized buffer pointer into this
+  /// Copies the elements of a fully initialized buffer pointer into this
   /// array at the specified position.
   ///
   /// The new elements are inserted before the element currently at the
@@ -311,7 +311,7 @@ extension UniqueArray {
     unsafe _storage.insert(copying: newElements, at: index)
   }
 
-  /// Copyies the elements of a fully initialized buffer pointer into this
+  /// Copies the elements of a fully initialized buffer pointer into this
   /// array at the specified position.
   ///
   /// The new elements are inserted before the element currently at the