docs: add a visualization notebook to BigFrame samples (#1675)

* write a notebook for visualization

* chore: add visualization notebook

* fix typo

* remove default project ID

* rename file and add an example with many params

* Add advanced plotting section

Author: sycai

notebooks/visualization/bq_dataframes_covid_line_graphs.ipynb

@@ -39,13 +39,13 @@
         "    </a>\n",
         "  </td>\n",
         "  <td>\n",
-        "    <a href=\"https://github.com/googleapis/python-bigquery-dataframes/tree/main/notebooks/dataframes/bq_dataframes_covid_line_graphs.ipynb\">\n",
+        "    <a href=\"https://github.com/googleapis/python-bigquery-dataframes/tree/main/notebooks/visualization/bq_dataframes_covid_line_graphs.ipynb\">\n",
         "      <img src=\"https://cloud.google.com/ml-engine/images/github-logo-32px.png\" alt=\"GitHub logo\">\n",
         "      View on GitHub\n",
         "    </a>\n",
         "  </td>\n",
         "  <td>\n",
-        "    <a href=\"https://console.cloud.google.com/bigquery/import?url=https://github.com/googleapis/python-bigquery-dataframes/tree/main/notebooks/dataframes/bq_dataframes_covid_line_graphs.ipynb\">\n",
+        "    <a href=\"https://console.cloud.google.com/bigquery/import?url=https://github.com/googleapis/python-bigquery-dataframes/tree/main/notebooks/visualization/bq_dataframes_covid_line_graphs.ipynb\">\n",
         "      <img src=\"https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTW1gvOovVlbZAIZylUtf5Iu8-693qS1w5NJw&s\" alt=\"BQ logo\" width=\"35\">\n",
         "      Open in BQ Studio\n",
         "    </a>\n",