use IServerStartup rather than class naming convention to register server service class

Oqtane.Server/Modules/HtmlText/Startup/ServerStartup.cs

@@ -0,0 +1,28 @@
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.DependencyInjection;
+using Oqtane.Infrastructure;
+using Oqtane.Modules.HtmlText.Repository;
+using Oqtane.Modules.HtmlText.Services;
+
+namespace Oqtane.Modules.HtmlText.Startup
+{
+    public class ServerStartup : IServerStartup
+    {
+        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
+        {
+            // not implemented
+        }
+
+        public void ConfigureMvc(IMvcBuilder mvcBuilder)
+        {
+            // not implemented
+        }
+
+        public void ConfigureServices(IServiceCollection services)
+        {
+            services.AddTransient<IHtmlTextService, ServerHtmlTextService>();
+            services.AddDbContextFactory<HtmlTextContext>(opt => { }, ServiceLifetime.Transient);
+        }
+    }
+}