Fixing "instructions" title

ImageColorizerColab.ipynb

@@ -160,10 +160,7 @@
   },
   {
    "cell_type": "markdown",
-   "metadata": {
-    "colab_type": "text",
-    "id": "BDFjbNxaadNJ"
-   },
+   "metadata": {},
    "source": [
     "#◢ Instructions"
    ]