Split online.cs and offline.csFile (#941)

Co-authored-by: 东风破 <birdfishs@163.com>

scripts/dotnet/OfflineRecognizerConfig.cs

@@ -0,0 +1,43 @@
+/// Copyright (c)  2024.5 by 东风破
+
+using System.Linq;
+using System.Collections.Generic;
+using System.Runtime.InteropServices;
+using System.Text;
+using System;
+
+namespace SherpaOnnx
+{
+
+    [StructLayout(LayoutKind.Sequential)]
+    public struct OfflineRecognizerConfig
+    {
+        public OfflineRecognizerConfig()
+        {
+            FeatConfig = new FeatureConfig();
+            ModelConfig = new OfflineModelConfig();
+            LmConfig = new OfflineLMConfig();
+
+            DecodingMethod = "greedy_search";
+            MaxActivePaths = 4;
+            HotwordsFile = "";
+            HotwordsScore = 1.5F;
+
+        }
+        public FeatureConfig FeatConfig;
+        public OfflineModelConfig ModelConfig;
+        public OfflineLMConfig LmConfig;
+
+        [MarshalAs(UnmanagedType.LPStr)]
+        public string DecodingMethod;
+
+        public int MaxActivePaths;
+
+        [MarshalAs(UnmanagedType.LPStr)]
+        public string HotwordsFile;
+
+        public float HotwordsScore;
+    }
+
+
+}