Add code example for CA1822 rule (#48964)

docs/fundamentals/code-analysis/quality-rules/ca1822.md

@@ -10,6 +10,8 @@ helpviewer_keywords:
 - CA1822
 author: gewarren
 ms.author: gewarren
+dev_langs:
+- CSharp
 ---
 # CA1822: Mark members as static
 
@@ -33,6 +35,10 @@ Members that do not access instance data or call instance methods can be marked
 
 Mark the member as static (or Shared in Visual Basic) or use 'this'/'Me' in the method body, if appropriate.
 
+## Example
+
+:::code language="csharp" source="snippets/csharp/all-rules/ca1822.cs" id="snippet1":::
+
 ## When to suppress warnings
 
 It is safe to suppress a warning from this rule for previously shipped code for which the fix would be a breaking change.

docs/fundamentals/code-analysis/quality-rules/snippets/csharp/all-rules/ca1822.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Collections.Generic;
+
+namespace ca1822
+{
+    //<snippet1>
+    public class Printer
+    {
+        private readonly List<char> _items = [
+            'H', 'e', 'l', 'l', 'o',
+        ];
+
+        public void PrintHello()
+        {
+            BadPrintHelloInternal();
+            GoodPrintHelloInternal();
+            GoodPrintHelloStaticInternal();
+        }
+
+        // This method violates the rule.
+        private void BadPrintHelloInternal()
+        {
+            Console.WriteLine("Hello");
+        }
+
+        // This methods satisfies the rule.
+        private void GoodPrintHelloInternal()
+        {
+            Console.WriteLine(string.Join(string.Empty, this._items));
+        }
+
+        private static void GoodPrintHelloStaticInternal()
+        {
+            Console.WriteLine("Hello");
+        }
+    }
+    //</snippet1>
+}