Add text to index

samples/core/get_started/_index.ipynb

@@ -61,7 +61,14 @@
       "source": [
         "# Get Started with TensorFlow\n",
         "\n",
-        "First, import TensorFlow into your program:"
+        "This is a [Google Colaboratory](https://colab.sandbox.google.com/notebooks/welcome.ipynb) notebook file. Python programs are run directly in the browser—a great way to learn and use TensorFlow. To run the Colab notebook:\n",
+        "\n",
+        "1. Connect to a Python runtime: At the top-right of the menubar, select *CONNECT*.\n",
+        "2. Run all the notebook code cells: Select *Runtime* > *Run all*.\n",
+        "\n",
+        "For more examples and guides, see [Get Started with TensorFlow](https://www.tensorflow.org/get_started/).\n",
+        "\n",
+        "Let's get started, import the TensorFlow library into your program:"
       ]
     },
     {
@@ -89,7 +96,7 @@
       },
       "cell_type": "markdown",
       "source": [
-        "Load and configure the [MNIST](http://yann.lecun.com/exdb/mnist/) dataset. Convert the samples from an int to a float:"
+        "Load and configure the [MNIST](http://yann.lecun.com/exdb/mnist/) dataset. Convert the samples from integers to a floating-point numbers:"
       ]
     },
     {
@@ -107,9 +114,9 @@
       "source": [
         "mnist = tf.keras.datasets.mnist\n",
         "\n",
-        "(X_train, y_train), (X_test, y_test) = mnist.load_data()\n",
+        "(x_train, y_train), (x_test, y_test) = mnist.load_data()\n",
         "\n",
-        "X_train, X_test = X_train / 255.0, X_test / 255.0"
+        "x_train, x_test = x_train / 255.0, x_test / 255.0"
       ],
       "execution_count": 0,
       "outputs": []
@@ -121,7 +128,7 @@
       },
       "cell_type": "markdown",
       "source": [
-        "Build the `tf.keras` model:"
+        "Build the `tf.keras` model by stacking layers. Select an optimizer and loss function used for training:"
       ]
     },
     {
@@ -174,12 +181,22 @@
       },
       "cell_type": "code",
       "source": [
-        "model.fit(X_train, y_train, epochs=5)\n",
+        "model.fit(x_train, y_train, epochs=5)\n",
         "\n",
-        "model.evaluate(X_test, y_test)"
+        "model.evaluate(x_test, y_test)"
       ],
       "execution_count": 0,
       "outputs": []
+    },
+    {
+      "metadata": {
+        "id": "T4JfEh7kvx6m",
+        "colab_type": "text"
+      },
+      "cell_type": "markdown",
+      "source": [
+        "See [Get Started with TensorFlow](https://www.tensorflow.org/get_started/) for next steps."
+      ]
     }
   ]
 }
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