Merged PR 21273: Add remark to CreateHash about keyMaterial value

Add remark to CreateHash about keyMaterial value.

This is to address GitHub issue [1322](#1322).

Author: alvinashcraft

windows.security.cryptography.core/macalgorithmprovider_createhash_851111259.md

@@ -10,17 +10,25 @@ public Windows.Security.Cryptography.Core.CryptographicHash CreateHash(Windows.S
 # Windows.Security.Cryptography.Core.MacAlgorithmProvider.CreateHash
 
 ## -description
+
 Creates a [CryptographicHash](cryptographichash.md) object that supports incremental hash operations.
 
 ## -parameters
+
 ### -param keyMaterial
+
 Random data used to help generate the hash. You can call the [GenerateRandom](../windows.security.cryptography/cryptographicbuffer_generaterandom_1645545930.md) method to create the random data.
 
 ## -returns
+
 A [CryptographicHash](cryptographichash.md) object that supports incremental hash operations.
 
 ## -remarks
 
+Note that using the same *keyMaterial* will result in the same hashes being produced by the returned **CryptographicHash** for the same input. The *keyMaterial* provided should be known data in order to re-create the hash later.
+
 ## -examples
 
 ## -see-also
+
+[GenerateRandom](../windows.security.cryptography/cryptographicbuffer_generaterandom_1645545930.md), [CryptographicHash](cryptographichash.md)