Add sample data file, fix URL

Author: demjened

notebooks/generative-ai/question-answering.ipynb

@@ -56,7 +56,7 @@
  "import json\n",
  "from urllib.request import urlopen\n",
  "\n",
- "url = \"https://raw.githubusercontent.com/elastic/elasticsearch-labs/main/esre-examples/python-flask-example/example-data/data.json\"\n",
+ "url = \"https://raw.githubusercontent.com/elastic/elasticsearch-labs/main/notebooks/generative-ai/sample_data/data.json\"\n",
  "\n",
  "response = urlopen(url)\n",
  "\n",