update sidebar

Author: stephen-net

docs/config/section-a/three.md

@@ -5,6 +5,16 @@
 
 This is the paragrap one.
 
+```csharp
+public class Program
+{
+    public static void Main(string[] args)
+    {
+        Console.WriteLine("hello");
+    }
+}
+```
+
 ## p2
 
 This is the paragrap two.