Add missing </td> to table block (#506)

Should fix Devsite MT issues

site/en/gemma/docs/codegemma/keras_quickstart.ipynb

@@ -49,6 +49,7 @@
         "<table class=\"tfo-notebook-buttons\" align=\"left\">\n",
         "  <td>\n",
         "    <a target=\"_blank\" href=\"https://ai.google.dev/gemma/docs/codegemma/keras_quickstart\"><img src=\"https://ai.google.dev/static/site-assets/images/docs/notebook-site-button.png\" height=\"32\" width=\"32\" />View on ai.google.dev</a>\n",
+        "  </td>\n",
         "  <td>\n",
         "    <a target=\"_blank\" href=\"https://colab.research.google.com/github/google/generative-ai-docs/blob/main/site/en/gemma/docs/codegemma/keras_quickstart.ipynb\"><img src=\"https://www.tensorflow.org/images/colab_logo_32px.png\" />Run in Google Colab</a>\n",
         "  </td>\n",