add api culture

OwnChar.App.Desktop/UI/Windows/MainWindowApi.cs

@@ -0,0 +1,23 @@
+using OwnChar.App.Desktop.Api;
+using System;
+using System.Windows.Forms;
+
+namespace OwnChar.App.Desktop.UI.Windows;
+
+public partial class MainWindow
+{
+    public class MainWindowApi(MainWindow mainWindow) : IMainWindowApi
+    {
+        public MainWindow MainWindow { get; } = mainWindow;
+
+        public void CloseTab(Control content)
+        {
+            throw new NotImplementedException();
+        }
+
+        public void OpenTab(Control content)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}