Corrected some links in the example notebook

example_slide.ipynb

@@ -442,7 +442,7 b''
       "\n",
       "I have a lot of work to do but this is an exciting beginning!\n",
       "\n",
-      "You can check [vIPer](http://www.viperapp.oquanta.info)."
+      "You can check [here](https://github.com/ipython/nbconvert/pull/63) for more information."
      ]
     },
     {