Address code review feedback: move example to separate file and fix punctuation

Co-authored-by: gewarren <[email protected]>

Author: Copilot

snippets/csharp/System.Security.Cryptography.X509Certificates/X509Chain/Overview/chainelements-ordering.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Security.Cryptography.X509Certificates;
+
+class ChainElementsOrdering
+{
+    static void DemonstrateChainElementsOrdering()
+    {
+//<SNIPPET6>
+        using var chain = new X509Chain();
+        chain.Build(serverCertificate);
+
+        // chain.ChainElements[0] is the leaf (end-entity) certificate
+        // chain.ChainElements[^1] is the root (trust anchor) certificate
+
+        Console.WriteLine("Certificate chain from leaf to root:");
+        for (int i = 0; i < chain.ChainElements.Count; i++)
+        {
+            var cert = chain.ChainElements[i].Certificate;
+            var role = i == 0 ? "Leaf" : 
+                       i == chain.ChainElements.Count - 1 ? "Root" : "Intermediate";
+            Console.WriteLine($"[{i}] {role}: {cert.Subject}");
+        }
+//</SNIPPET6>
+    }
+}

xml/System.Security.Cryptography.X509Certificates/X509Chain.xml

@@ -467,27 +467,12 @@
  The `ChainElements` collection is ordered from the end-entity (leaf) certificate at index 0, through any intermediate certificates, to the trust anchor (root certificate) at the final index. This ordering is consistent across all platforms:
 
  - On Windows, this matches the `CERT_CHAIN_CONTEXT` structure where `rgpChain[0]` is the end certificate and `rgpChain[cChain–1]` is the final chain element (root).
- - On Linux and macOS, this matches OpenSSL's `X509_STORE_CTX_get0_chain()` which returns a `STACK_OF(X509)` ordered from leaf to root.
+ - On Linux and macOS, this matches OpenSSL's `X509_STORE_CTX_get0_chain()`, which returns a `STACK_OF(X509)` ordered from leaf to root.
 
 ## Examples
- The following code example demonstrates the ordering of chain elements:
-
- ```csharp
- using var chain = new X509Chain();
- chain.Build(serverCertificate);
-
- // chain.ChainElements[0] is the leaf (end-entity) certificate
- // chain.ChainElements[^1] is the root (trust anchor) certificate
-
- Console.WriteLine("Certificate chain from leaf to root:");
- for (int i = 0; i < chain.ChainElements.Count; i++)
- {
-     var cert = chain.ChainElements[i].Certificate;
-     var role = i == 0 ? "Leaf" : 
-                i == chain.ChainElements.Count - 1 ? "Root" : "Intermediate";
-     Console.WriteLine($"[{i}] {role}: {cert.Subject}");
- }
- ```
+The following code example demonstrates the ordering of chain elements:
+
+:::code language="csharp" source="~/snippets/csharp/System.Security.Cryptography.X509Certificates/X509Chain/Overview/chainelements-ordering.cs" id="Snippet6":::
 
  The following code example opens the current user's personal certificate store, allows you to select a certificate, then writes certificate and certificate chain information to the console. The output depends on the certificate you select.