Add returns and params docs for SyncPermissionsAsync

src/Discord.Net.Core/Entities/Channels/INestedChannel.cs

@@ -26,10 +26,14 @@ namespace Discord
         ///     representing the parent of this channel; <c>null</c> if none is set.
         /// </returns>
         Task<ICategoryChannel> GetCategoryAsync(CacheMode mode = CacheMode.AllowDownload, RequestOptions options = null);
-        
+
         /// <summary>
         ///     Syncs the permissions of this nested channel with its parent's.
         /// </summary>
+        /// <param name="options">The options to be used when sending the request.</param>
+        /// <returns>
+        ///     A task that represents the asynchronous operation for syncing channel permissions with its parent's.
+        /// </returns>
         Task SyncPermissionsAsync(RequestOptions options = null);
 
         /// <summary>