Delete the docs for the on_submit method.

Author: jasongrout

docs/source/examples/Widget Events.ipynb

@@ -124,63 +124,27 @@
     }
    },
    "source": [
-    "### on_submit"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "The `Text` widget also has a special `on_submit` event.  The `on_submit` event fires when the user hits return."
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 4,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "application/vnd.jupyter.widget-view+json": {
-       "model_id": "cab0a6538a00491f95c48e77707e9ad8"
-      }
-     },
-     "metadata": {},
-     "output_type": "display_data"
-    }
-   ],
-   "source": [
-    "text = widgets.Text()\n",
-    "display(text)\n",
-    "\n",
-    "def handle_submit(sender):\n",
-    "    print(text.value)\n",
-    "\n",
-    "text.on_submit(handle_submit)"
+    "## Traitlet events"
    ]
   },
   {
    "cell_type": "markdown",
    "metadata": {
-    "slideshow": {
-     "slide_type": "slide"
-    }
+    "deletable": true,
+    "editable": true
    },
-   "source": [
-    "## Traitlet events"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
    "source": [
     "Widget properties are IPython traitlets and traitlets are eventful.  To handle  changes, the `observe` method of the widget can be used to register a callback.  The doc string for `observe` can be seen below."
    ]
   },
   {
    "cell_type": "code",
    "execution_count": 5,
-   "metadata": {},
+   "metadata": {
+    "collapsed": false,
+    "deletable": true,
+    "editable": true
+   },
    "outputs": [
     {
      "name": "stdout",