Removed nested classifications for python annotation tools

Author: ovalle15

examples/annotation_import/text.ipynb

@@ -232,20 +232,7 @@
     {
       "cell_type": "code",
       "source": [
-        "########## Classification - Radio (with subclassifcations) ##########\n",
-        "\n",
-        "# Python annotation\n",
-        "radio_annotation_nested = ClassificationAnnotation(\n",
-        "    name=\"radio_question_sub\", \n",
-        "    value=Radio(answer = ClassificationAnswer(name = \"first_radio_answer\")),\n",
-        "    classifications=[\n",
-        "    \tClassificationAnnotation(\n",
-        "        \tname=\"sub_radio_question\",\n",
-        "      \t\tvalue=Radio(answer=ClassificationAnswer(name=\"first_sub_radio_answer\"))\n",
-        "      )\n",
-        "    ]\n",
-        ")\n",
-        "\n",
+        "########## Nested Classifications are only supported with NDJSON tools ##########\n",
         "\n",
         "# NDJSON\n",
         "radio_annotation_ndjson_with_subclass = {\n",