add summary comment.

src/DotNetCore.CAP/IStorage.cs

@@ -14,8 +14,14 @@ namespace DotNetCore.CAP
         /// </summary>
         Task InitializeAsync(CancellationToken cancellationToken);
 
+        /// <summary>
+        /// Provider the dashboard metric api.
+        /// </summary>
         IMonitoringApi GetMonitoringApi();
 
+        /// <summary>
+        /// Storage connection of database operate.
+        /// </summary>
         IStorageConnection GetConnection();
     }
 }

src/DotNetCore.CAP/IStorageTransaction.cs

@@ -4,6 +4,10 @@ using DotNetCore.CAP.Models;
 
 namespace DotNetCore.CAP
 {
+    /// <summary>
+    /// A transactional database storage operation.
+    /// Update message state of the message table with transactional.
+    /// </summary>
     public interface IStorageTransaction : IDisposable
     {
         void UpdateMessage(CapPublishedMessage message);