Add project files.

ConstructorApp.BusinessLayer/Abstract/IProjectService.cs

@@ -0,0 +1,13 @@
+using ConstructorApp.EntityLayer.Entities;
+
+namespace ConstructorApp.BusinessLayer.Abstract
+{
+    public interface IProjectService : IGenericService<Project>
+    {
+        void TProjectStatusActive(int id);
+        void TProjectStatusPassive(int id);
+        int TCountAll();
+        Project TGetBySlug(string slug);
+        Project TGetProjectWithImagesBySlug(string slug);
+    }
+}