replace msdn async link (#4322)

Author: mairaw

xml/System.Runtime.CompilerServices/AsyncStateMachineAttribute.xml

@@ -53,7 +53,7 @@
   
  When a method (*MethodName*) has the Async or async modifier, the compiler emits IL that includes a state machine structure. This structure contains the code in the method. That IL also contains a stub method (*MethodName*) that calls into the state machine. The compiler adds the `AsyncStateMachine` attribute to the stub method so that tools can identify the corresponding state machine. Details of the emitted IL might change in future releases of the compilers.  
   
- For information about the Async feature, see [Asynchronous Programming with Async and Await](https://msdn.microsoft.com/library/db854f91-ccef-4035-ae4d-0911fde808c7).  
+ For information about the Async feature, see [Asynchronous programming (C#)](/dotnet/csharp/async) or [Asynchronous programming with Async and Await (Visual Basic)](/dotnet/visual-basic/programming-guide/concepts/async/).  
   
    
   

xml/System.Security.Cryptography/CryptoStream.xml

@@ -811,7 +811,7 @@
           <format type="text/markdown"><![CDATA[  
   
 ## Remarks  
- You must preface your call to <xref:System.Security.Cryptography.CryptoStream.FlushAsync%2A> with the `await` (C#) or `Await` (Visual Basic) operator to suspend execution of the method until the task is complete. For more information, see [Asynchronous Programming with Async and Await](https://msdn.microsoft.com/library/db854f91-ccef-4035-ae4d-0911fde808c7).  
+ You must preface your call to <xref:System.Security.Cryptography.CryptoStream.FlushAsync%2A> with the `await` (C#) or `Await` (Visual Basic) operator to suspend execution of the method until the task is complete. For more information, see [Asynchronous programming (C#)](/dotnet/csharp/async) or [Asynchronous programming with Async and Await (Visual Basic)](/dotnet/visual-basic/programming-guide/concepts/async/).  
   
  If the operation is canceled before it completes, the returned task contains the <xref:System.Threading.Tasks.TaskStatus.Canceled> value for the <xref:System.Threading.Tasks.Task.Status%2A> property.  
   
@@ -1111,7 +1111,7 @@
           <format type="text/markdown"><![CDATA[  
   
 ## Remarks  
- You must preface your call to <xref:System.Security.Cryptography.CryptoStream.ReadAsync%2A> with the `await` (C#) or `Await` (Visual Basic) operator to suspend execution of the method until the task is complete. For more information, see [Asynchronous Programming with Async and Await](https://msdn.microsoft.com/library/db854f91-ccef-4035-ae4d-0911fde808c7).  
+ You must preface your call to <xref:System.Security.Cryptography.CryptoStream.ReadAsync%2A> with the `await` (C#) or `Await` (Visual Basic) operator to suspend execution of the method until the task is complete. For more information, see [Asynchronous programming (C#)](/dotnet/csharp/async) or [Asynchronous programming with Async and Await (Visual Basic)](/dotnet/visual-basic/programming-guide/concepts/async/).  
   
  If the operation is canceled before it completes, the returned task contains the <xref:System.Threading.Tasks.TaskStatus.Canceled> value for the <xref:System.Threading.Tasks.Task.Status%2A> property.  
   
@@ -1406,7 +1406,7 @@
           <format type="text/markdown"><![CDATA[  
   
 ## Remarks  
- You must preface your call to <xref:System.Security.Cryptography.CryptoStream.WriteAsync%2A> with the `await` (C#) or `Await` (Visual Basic) operator to suspend execution of the method until the task is complete. For more information, see [Asynchronous Programming with Async and Await](https://msdn.microsoft.com/library/db854f91-ccef-4035-ae4d-0911fde808c7).  
+ You must preface your call to <xref:System.Security.Cryptography.CryptoStream.WriteAsync%2A> with the `await` (C#) or `Await` (Visual Basic) operator to suspend execution of the method until the task is complete. For more information, see [Asynchronous programming (C#)](/dotnet/csharp/async) or [Asynchronous programming with Async and Await (Visual Basic)](/dotnet/visual-basic/programming-guide/concepts/async/).  
   
  If the operation is canceled before it completes, the returned task contains the <xref:System.Threading.Tasks.TaskStatus.Canceled> value for the <xref:System.Threading.Tasks.Task.Status%2A> property.  
   

xml/System.Xml/XmlDictionaryWriter.xml

@@ -2075,7 +2075,8 @@ binarywriter.WriteEndAttribute();
 -or-
 
 An <see cref="T:System.Xml.XmlDictionaryWriter" /> asynchronous method was called without setting the <see cref="P:System.Xml.XmlWriterSettings.Async" /> flag to <see langword="true" />. In this case, <see cref="T:System.InvalidOperationException" /> is thrown with the message "Set XmlWriterSettings.Async to true if you want to use Async Methods."</exception>
-        <related type="Article" href="https://msdn.microsoft.com/library/db854f91-ccef-4035-ae4d-0911fde808c7">Asynchronous Programming with Async and Await (C# and Visual Basic)</related>
+        <related type="Article" href="/dotnet/csharp/async">Asynchronous programming (C#)</related>
+        <related type="Article" href="/dotnet/visual-basic/programming-guide/concepts/async/">Asynchronous programming with Async and Await (Visual Basic)</related>
       </Docs>
     </Member>
     <MemberGroup MemberName="WriteElementString">
@@ -2887,7 +2888,8 @@ An <see cref="T:System.Xml.XmlDictionaryWriter" /> asynchronous method was calle
 -or-
 
 An <see cref="T:System.Xml.XmlDictionaryWriter" /> asynchronous method was called without setting the <see cref="P:System.Xml.XmlWriterSettings.Async" /> flag to <see langword="true" />. In this case, <see cref="T:System.InvalidOperationException" /> is thrown with the message "Set XmlWriterSettings.Async to true if you want to use Async Methods."</exception>
-        <related type="Article" href="https://msdn.microsoft.com/library/db854f91-ccef-4035-ae4d-0911fde808c7">Asynchronous Programming with Async and Await (C# and Visual Basic)</related>
+        <related type="Article" href="/dotnet/csharp/async">Asynchronous programming (C#)</related>
+        <related type="Article" href="/dotnet/visual-basic/programming-guide/concepts/async/">Asynchronous programming with Async and Await (Visual Basic)</related>
       </Docs>
     </Member>
     <MemberGroup MemberName="WriteXmlAttribute">