add colab buttons to notebooks (#468)

notebooks/detoxify-evaluation/DetoxityEvaluation.ipynb

@@ -1,5 +1,23 @@
 {
  "cells": [
+  {
+   "attachments": {},
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "[![Open In Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/LAION-AI/Open-Assistant/blob/main/notebooks/detoxify-evaluation/DetoxityEvaluation.ipynb)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# uncomment below to install required python packages\n",
+    "#!pip install detoxify"
+   ]
+  },
   {
    "attachments": {},
    "cell_type": "markdown",