feat: hide input in display

Set the hide_input metadata field in the notebook to hide input in the
renderer. This can be removed when the UI renderer is upgraded to
understand the report-mode feature of papermill.

notebooks/Dashboard.ipynb

@@ -340,6 +340,7 @@
   }
  ],
  "metadata": {
+  "hide_input": true,
   "kernelspec": {
    "display_name": "Python 3",
    "language": "python",
@@ -355,7 +356,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.7.6"
+   "version": "3.7.3"
   }
  },
  "nbformat": 4,