Add foundation

Toolkit.Foundation/IHostBuilderExtensions.cs

@@ -0,0 +1,19 @@
+using Microsoft.Extensions.Hosting;
+
+namespace Toolkit.Foundation;
+
+public static class IHostBuilderExtensions
+{
+    public static IHostBuilder UseContentRoot(this IHostBuilder hostBuilder, 
+        string contentRoot,
+        bool createDirectory)
+    {
+        if (createDirectory)
+        { 
+            Directory.CreateDirectory(contentRoot);
+        }
+
+        hostBuilder.UseContentRoot(contentRoot);
+        return hostBuilder;
+    }
+}