Added instruction to setup the environment via pip reqs

01 - Preliminaries.ipynb

@@ -160,7 +160,11 @@
     "    - `pip install matplotlib`\n",
     "    - `pip install \"ipython[all]\"  # don't forget the quotation!`\n",
     "    - `pip install scikit-learn`\n",
-    "    - `pip install numexpr`"
+    "    - `pip install numexpr`\n",
+    "    \n",
+    "    **OR**\n",
+    "    \n",
+    "    - `pip install -r requirements.txt`"
    ]
   },
   {