Update 03-ELSER.ipynb: Fix wrong lookup (#65)

Fix lookup of field that failed because https://raw.githubusercontent.com/elastic/elasticsearch-labs/main/notebooks/search/movies.json does not contain `text` but only the `field` plot

Author: herrBez

notebooks/search/03-ELSER.ipynb

@@ -427,8 +427,8 @@
  " doc_id = hit['_id']\n",
  " score = hit['_score']\n",
  " title = hit['_source']['title']\n",
- " text = hit['_source']['text']\n",
- " print(f\"Score: {score}\\nTitle: {title}\\nPlot: {text}\\n\")"
+ " plot = hit['_source']['plot']\n",
+ " print(f\"Score: {score}\\nTitle: {title}\\nPlot: {plot}\\n\")"
  ]
  }
  ],