Fix typo in path of the network image.

PiperOrigin-RevId: 428645182

Author: tensorflower-gardener

site/en/tutorials/customization/custom_training_walkthrough.ipynb

@@ -365,7 +365,7 @@
         "\n",
         "<table>\n",
         "  <tr><td>\n",
-        "    <img src=\"https://wwtensorflow.org/tutorials/customization/images/full_network_penguin.png\" alt=\"A diagram of the network architecture: Inputs, 2 hidden layers, and outputs\"\n",
+        "    <img src=\"https://www.tensorflow.org/tutorials/customization/images/full_network_penguin.png\" alt=\"A diagram of the network architecture: Inputs, 2 hidden layers, and outputs\"\n",
         "     class=\"no-filter\">\n",
         "  </td></tr>\n",
         "  <tr><td align=\"center\">\n",