Updated docs on CopyTo(Stream, Int32) (#7966)

The old documentation did not make it clear that the write or read positions were advanced at all. This can lead to a lot of confusion for programmers when they attempt to use this method.

Author: Shailosingh

xml/System.IO/Stream.xml

@@ -655,7 +655,7 @@
         <AssemblyVersion>4.1.0.0</AssemblyVersion>
       </AssemblyInfo>
       <Docs>
-        <summary>Reads the bytes from the current stream and writes them to another stream.</summary>
+        <summary>Reads the bytes from the current stream and writes them to another stream. Both streams positions are advanced by the number of bytes copied.</summary>
       </Docs>
     </MemberGroup>
     <Member MemberName="CopyTo">
@@ -699,7 +699,7 @@
       </Parameters>
       <Docs>
         <param name="destination">The stream to which the contents of the current stream will be copied.</param>
-        <summary>Reads the bytes from the current stream and writes them to another stream.</summary>
+        <summary>Reads the bytes from the current stream and writes them to another stream. Both streams positions are advanced by the number of bytes copied.</summary>
         <remarks>
           <format type="text/markdown"><![CDATA[  
   
@@ -775,7 +775,7 @@
       <Docs>
         <param name="destination">The stream to which the contents of the current stream will be copied.</param>
         <param name="bufferSize">The size of the buffer. This value must be greater than zero. The default size is 81920.</param>
-        <summary>Reads the bytes from the current stream and writes them to another stream, using a specified buffer size.</summary>
+        <summary>Reads the bytes from the current stream and writes them to another stream, using a specified buffer size. Both streams positions are advanced by the number of bytes copied.</summary>
         <remarks>
           <format type="text/markdown"><![CDATA[  
   
@@ -805,7 +805,7 @@
         <AssemblyVersion>4.1.0.0</AssemblyVersion>
       </AssemblyInfo>
       <Docs>
-        <summary>Asynchronously reads the bytes from the current stream and writes them to another stream.</summary>
+        <summary>Asynchronously reads the bytes from the current stream and writes them to another stream. Both streams positions are advanced by the number of bytes copied.</summary>
       </Docs>
     </MemberGroup>
     <Member MemberName="CopyToAsync">
@@ -855,7 +855,7 @@
       </Parameters>
       <Docs>
         <param name="destination">The stream to which the contents of the current stream will be copied.</param>
-        <summary>Asynchronously reads the bytes from the current stream and writes them to another stream.</summary>
+        <summary>Asynchronously reads the bytes from the current stream and writes them to another stream. Both streams positions are advanced by the number of bytes copied.</summary>
         <returns>A task that represents the asynchronous copy operation.</returns>
         <remarks>
           <format type="text/markdown"><![CDATA[  
@@ -930,7 +930,7 @@
       <Docs>
         <param name="destination">The stream to which the contents of the current stream will be copied.</param>
         <param name="bufferSize">The size, in bytes, of the buffer. This value must be greater than zero. The default size is 81920.</param>
-        <summary>Asynchronously reads the bytes from the current stream and writes them to another stream, using a specified buffer size.</summary>
+        <summary>Asynchronously reads the bytes from the current stream and writes them to another stream, using a specified buffer size. Both streams positions are advanced by the number of bytes copied.</summary>
         <returns>A task that represents the asynchronous copy operation.</returns>
         <remarks>
           <format type="text/markdown"><![CDATA[  
@@ -988,7 +988,7 @@
       <Docs>
         <param name="destination">The stream to which the contents of the current stream will be copied.</param>
         <param name="cancellationToken">The token to monitor for cancellation requests. The default value is <see cref="P:System.Threading.CancellationToken.None" />.</param>
-        <summary>Asynchronously reads the bytes from the current stream and writes them to another stream, using a specified cancellation token.</summary>
+        <summary>Asynchronously reads the bytes from the current stream and writes them to another stream, using a specified cancellation token. Both streams positions are advanced by the number of bytes copied.</summary>
         <returns>A task that represents the asynchronous copy operation.</returns>
         <remarks>
           <format type="text/markdown"><![CDATA[  
@@ -1057,7 +1057,7 @@
         <param name="destination">The stream to which the contents of the current stream will be copied.</param>
         <param name="bufferSize">The size, in bytes, of the buffer. This value must be greater than zero. The default size is 81920.</param>
         <param name="cancellationToken">The token to monitor for cancellation requests. The default value is <see cref="P:System.Threading.CancellationToken.None" />.</param>
-        <summary>Asynchronously reads the bytes from the current stream and writes them to another stream, using a specified buffer size and cancellation token.</summary>
+        <summary>Asynchronously reads the bytes from the current stream and writes them to another stream, using a specified buffer size and cancellation token. Both streams positions are advanced by the number of bytes copied.</summary>
         <returns>A task that represents the asynchronous copy operation.</returns>
         <remarks>
           <format type="text/markdown"><![CDATA[