Improve how to host McpServer (#30)

src/mcpdotnet/Configuration/IMcpServerBuilder.cs

@@ -0,0 +1,15 @@
+using McpDotNet.Server;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace McpDotNet.Configuration;
+
+/// <summary>
+/// Builder for configuring <see cref="IMcpServer"/> instances.
+/// </summary>
+public interface IMcpServerBuilder
+{
+    /// <summary>
+    /// Gets the service collection.
+    /// </summary>
+    IServiceCollection Services { get; }
+}