Move samples to dedicated repository

Samples are now in https://github.com/open-maui/maui-linux-samples

This keeps the framework repo focused and allows samples to:
- Reference NuGet package (real-world usage)
- Be cloned independently
- Have their own release cycle

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

samples/ShellDemo/MauiProgram.cs

@@ -1,24 +0,0 @@
-// MauiProgram.cs - Shared MAUI app configuration
-// Works across all platforms (iOS, Android, Windows, Linux)
-
-using Microsoft.Maui.Hosting;
-using Microsoft.Maui.Platform.Linux.Hosting;
-
-namespace ShellDemo;
-
-public static class MauiProgram
-{
-    public static MauiApp CreateMauiApp()
-    {
-        var builder = MauiApp.CreateBuilder();
-        
-        // Configure the app (shared across all platforms)
-        builder.UseMauiApp<App>();
-        
-        // Add Linux platform support
-        // On other platforms, this would be iOS/Android/Windows specific
-        builder.UseLinux();
-        
-        return builder.Build();
-    }
-}