Fix readme

getting_started.ipynb

@@ -213,7 +213,8 @@
    "metadata": {},
    "source": [
     "```\n",
-    "    python3 download_data.py [TOKEN]\n",
+    "    pip install -r requirements.txt\n",
+    "    python download_data.py [TOKEN]\n",
     "```"
    ]
   },