Added links to other notebooks

Author: chryswoods

01_jupyter_howto.ipynb

@@ -121,7 +121,7 @@
    "source": [
     "You can rotate and interact with molecules once they have loaded (the \"[*]\" next to a cell indicates that it is processing. It will turn into a number once processing is complete)\n",
     "\n",
-    "You can change molecular representations and interact with the 3D molecule view. Later on we will go through some examples showing what you can do and how you can select parts of the molecule.\n",
+    "You can change molecular representations and interact with the 3D molecule view. [Later on](16_viewing_molecules.ipynb) we will go through some examples showing what you can do and how you can select parts of the molecule (or [click here](16_viewing_molecules.ipynb) if you want to jump ahead and learn now).\n",
     "\n",
     "In addition to viewing molecules, you can also draw graphs. This is achieved using a combination of the [matplotlib](https://matplotlib.org), [numpy](http://www.numpy.org) and [pandas](https://pandas.pydata.org) modules. For example, the below code draws a sine and cosine curve."
    ]
@@ -151,7 +151,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "Later on we will go through pandas, matplotlib and numpy and you will learn how to draw lots of different and interesting graphs."
+    "Later on we will go through [pandas](12_pandas.ipynb), [matplotlib](15_matplotlib.ipynb) and [numpy](13_basic_numpy.ipynb) and you will learn how to draw lots of different and interesting graphs (or click the links to jump ahead and learn now)."
    ]
   },
   {

13_basic_numpy.ipynb

@@ -365,6 +365,13 @@
    "metadata": {},
    "outputs": [],
    "source": []
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "There is [still more numpy to learn](14_more_numpy.ipynb)"
+   ]
   }
  ],
  "metadata": {