description about parameter h added

ml3/2_4_1_Exercise.ipynb

@@ -275,7 +275,10 @@
     "print(classification_report(y_test, lr_preds))\n",
     "\n",
     "plt.figure(figsize=(10,7))\n",
-    "plot_decision_surface(X, y, lr)"
+    "# This methods outputs a visualization\n",
+    "# the h parameter adjusts the precision of the visualization\n",
+    "# if you find memory errors, set h to a higher value (e.g., h=0.1)\n",
+    "plot_decision_surface(X, y, lr, h=0.02) "
    ]
   },
   {