Add some text to colab to help people troubleshoot issues.

notebooks/comfyui_colab.ipynb

@@ -85,7 +85,12 @@
     {
       "cell_type": "markdown",
       "source": [
-        "Run ComfyUI (use the fp16 model configs for more speed):"
+        "### Run ComfyUI \n",
+        "use the **fp16** model configs for more speed\n",
+        "\n",
+        "You should see the ui appear in an iframe. If you get a 403 error, it's your firefox settings or an extension that's messing things up.\n",
+        "\n",
+        "If you want to open it in another window use the second link not the first one.\n"
       ],
       "metadata": {
         "id": "gggggggggg"