Add opt-out of cookies/gdpr

[marcinczeczko]

Add to the last item before the </body> tag:

However, the colors of text,border & background need to be tweaked to knotx colors

<link rel="stylesheet" type="text/css" href="//cdnjs.cloudflare.com/ajax/libs/cookieconsent2/3.0.3/cookieconsent.min.css" />
+<script src="//cdnjs.cloudflare.com/ajax/libs/cookieconsent2/3.0.3/cookieconsent.min.js"></script>
+<script>
+window.addEventListener("load", function(){
+window.cookieconsent.initialise({
+  "palette": {
+    "popup": {
+      "background": "#64386b",
+      "text": "#ffcdfd"
+    },
+    "button": {
+      "background": "transparent",
+      "text": "#f8a8ff",
+      "border": "#f8a8ff"
+    }
+  },
+  "content": {
+    "message": "This website uses anonymous cookies to ensure we provide you the best experience. ",
+    "link": "Opt out!",
+    "href": "https://tools.google.com/dlpage/gaoptout/"
+  }
+})});
+</script>