added transform entry in deep learning history table

08_a-neural_networks.ipynb

@@ -67,7 +67,8 @@
     "| 1997 | Long-short term memory (LSTM) model |\n",
     "| 1998 | LeNet-5 |\n",
     "| 2014 | Gated Recurrent Units (GRU), Generative Adversarial Networks (GAN) |\n",
-    "| 2015 | ResNet |"
+    "| 2015 | ResNet |\n",
+    "| 2017 | Transformer model is proposed |"
    ]
   },
   {