extensibility enhancements for site templates

Oqtane.Client/Startup.cs

@@ -58,6 +58,7 @@ namespace Oqtane.Client
             services.AddScoped<INotificationService, NotificationService>();
             services.AddScoped<IFolderService, FolderService>();
             services.AddScoped<IFileService, FileService>();
+            services.AddScoped<ISiteTemplateService, SiteTemplateService>();
 
             // dynamically register module contexts and repository services
             Assembly[] assemblies = AppDomain.CurrentDomain.GetAssemblies();