Add connected startup support

src/Connected.Components.Showcase/ClientStartup.cs

@@ -0,0 +1,25 @@
+using Connected.Startup;
+using Microsoft.AspNetCore.Components.WebAssembly.Hosting;
+using Microsoft.Extensions.DependencyInjection;
+using Connected.Services;
+
+namespace Connected.Components.Showcase;
+
+public class ClientStartup : IStartup
+{
+	public static IServiceProvider Services { get; private set; } = default!;
+
+	public async Task Configure(WebAssemblyHost host)
+	{
+		Services = host.Services;
+		
+		await Task.CompletedTask;
+	}
+
+	public async Task ConfigureServices(IServiceCollection services)
+	{
+		services.AddUIComponentServices();
+
+		await Task.CompletedTask;
+	}
+}