Rough version of Saving Series, Volumes, and MangaFiles to the DB. Relies on Cascaded delete rather than manually handling updating of file changes.

API/Interfaces/ISeriesRepository.cs

@@ -0,0 +1,14 @@
+using System.Threading.Tasks;
+using API.Entities;
+
+namespace API.Interfaces
+{
+    public interface ISeriesRepository
+    {
+        void Update(Series series);
+        Task<bool> SaveAllAsync();
+        Task<Series> GetSeriesByNameAsync(string name);
+        Series GetSeriesByName(string name);
+        bool SaveAll();
+    }
+}