fix nstructions on loading mpl style from json

Author: y-p

Chapter1_Introduction/Chapter1_Introduction.ipynb

@@ -193,7 +193,7 @@
       "\n",
       "            import json\n",
       "            s = json.load( open(\"../styles/bmh_matplotlibrc.json\") )\n",
-      "            matplotlib.RcParams.update(s)\n",
+      "            matplotlib.rcParams.update(s)\n",
       "\"\"\"\n",
       "\n",
       "figsize( 12, 4 )\n",