added a static load method for MnistModelLoader

src/TensorFlowHub/MnistModelLoader.cs

@@ -15,6 +15,16 @@ namespace Tensorflow.Hub
         private const string TEST_IMAGES = "t10k-images-idx3-ubyte.gz";
         private const string TEST_LABELS = "t10k-labels-idx1-ubyte.gz";
 
+        public static async Task<Datasets<MnistDataSet>> LoadAsync(string trainDir, bool oneHot = false)
+        {
+            var loader = new MnistModelLoader();
+            return await loader.LoadAsync(new ModelLoadSetting
+            {
+                TrainDir = trainDir,
+                OneHot = oneHot
+            });
+        }
+
         public async Task<Datasets<MnistDataSet>> LoadAsync(ModelLoadSetting setting)
         {
             if (setting.TrainSize.HasValue && setting.ValidationSize >= setting.TrainSize.Value)