docs: create a block to show how to export parameter to environment in terminal

examples/vector_databases/qdrant/QA_with_Langchain_Qdrant_and_OpenAI.ipynb

@@ -122,7 +122,16 @@
     "\n",
     "If you don't have an OpenAI API key, you can get one from [https://beta.openai.com/account/api-keys](https://beta.openai.com/account/api-keys).\n",
     "\n",
-    "Once you get your key, please add it to your environment variables as `OPENAI_API_KEY`."
+    "Once you get your key, please add it to your environment variables as `OPENAI_API_KEY` by running following command:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "! export OPENAI_API_KEY=\"your API key\""
    ]
   },
   {