follow same pattern as core framework

Oqtane.Server/wwwroot/Modules/Templates/External/Client/Services/[Module]Service.cs

@@ -7,6 +7,19 @@ using Oqtane.Shared;
 
 namespace [Owner].Module.[Module].Services
 {
+    public interface I[Module]Service 
+    {
+        Task<List<Models.[Module]>> Get[Module]sAsync(int ModuleId);
+
+        Task<Models.[Module]> Get[Module]Async(int [Module]Id, int ModuleId);
+
+        Task<Models.[Module]> Add[Module]Async(Models.[Module] [Module]);
+
+        Task<Models.[Module]> Update[Module]Async(Models.[Module] [Module]);
+
+        Task Delete[Module]Async(int [Module]Id, int ModuleId);
+    }
+
     public class [Module]Service : ServiceBase, I[Module]Service
     {
         public [Module]Service(HttpClient http, SiteState siteState) : base(http, siteState) { }