Wrap punctuation APIs to C#. (#945)

scripts/dotnet/OfflinePunctuationConfig.cs

@@ -0,0 +1,21 @@
+/// Copyright (c)  2024  Xiaomi Corporation (authors: Fangjun Kuang)
+
+using System.Linq;
+using System.Collections.Generic;
+using System.Runtime.InteropServices;
+using System.Text;
+using System;
+
+namespace SherpaOnnx
+{
+    [StructLayout(LayoutKind.Sequential)]
+    public struct OfflinePunctuationConfig
+    {
+        public OfflinePunctuationConfig()
+        {
+            Model = new OfflinePunctuationModelConfig();
+        }
+        public OfflinePunctuationModelConfig Model;
+    }
+}
+