fix image

Author: mvdebolskiy

docs/learning/notebooks/markdown_example.ipynb

@@ -103,10 +103,14 @@
     "To add a local image:\n",
     "\n",
     "```md\n",
-    "![Zeppelin](./Zeppelin.jpg) \n",
+    "![Zeppelin](./ZeppStatMay2014d.jpg) \n",
     "```\n",
-    "![Zeppelin](../../../_build/_images/Zeppelin.jpg)\n",
-    "\n"
+    "or for an image on the web:\n",
+    "```md\n",
+    "![Zeppelin](https://nilu.com/wp-content/uploads/2018/05/ZeppStatMay2014d.jpg)\n",
+    "```\n",
+    "\n",
+    "![Zeppelin](https://nilu.com/wp-content/uploads/2018/05/ZeppStatMay2014d.jpg)\n"
    ]
   },
   {