Removed metadata to hide cells with plot function declaration in UE tutorial

Author: Cristiano Köhler

doc/tutorials/unitary_event_analysis.ipynb

@@ -71,19 +71,15 @@
   },
   {
    "cell_type": "markdown",
-   "metadata": {
-    "nbsphinx": "hidden"
-   },
+   "metadata": {},
    "source": [
     "# Write a plotting function"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "metadata": {
-    "nbsphinx": "hidden"
-   },
+   "metadata": {},
    "outputs": [],
    "source": [
     "# borrowed from Viziphant\n",