Add XML comments to public entities.

Aaru.Database/Models/BaseModel.cs

@@ -34,8 +34,14 @@ using System.ComponentModel.DataAnnotations;
 
 namespace Aaru.Database.Models
 {
+    /// <summary>
+    /// Base database model
+    /// </summary>
     public abstract class BaseModel
     {
+        /// <summary>
+        /// Database ID
+        /// </summary>
         [Key]
         public int Id { get; set; }
     }