[docs] refactor measure docs syntax highlighting

Author: addyosmani

site/src/measure.njk

@@ -16,15 +16,16 @@ In this section, we explore different ways of measuring the impact of Quicklink
 - An [optimized version of the site](https://mini-ecomm-quicklink.glitch.me/), which is a copy of the original version, but this time, using Quicklink in the listing page, to prefetch links that come to the view. You can view and edit the code, in the [Glitch project](https://glitch.com/edit/#!/mini-ecomm-quicklink?path=server.js:1:0).
 
 If you take a look at the code of the listing page, in the optimized version of the site, you'll find the code to initialize Quicklink:
-
-```js
-  <script src="https://unpkg.com/[email protected]/dist/quicklink.umd.js"></script>
-    <script>
-      window.addEventListener('load', () =>{
-        quicklink.listen();
-    });
-  </script>
-```
+{% endmarkdownConvert %}
+  {% highlight "js" %}
+<script src="https://unpkg.com/quicklink@{{ site.quicklinkVersion }}/dist/quicklink.umd.js"></script>
+<script>
+  window.addEventListener('load', () =>{
+    quicklink.listen();
+  });
+</script>
+  {% endhighlight %}
+{% markdownConvert %}
 ## Using Chrome DevTools
 
 The first tool you’ll use is [Chrome DevTools](https://developers.google.com/web/tools/chrome-devtools), which is useful both for local development, and also for production URLs.
@@ -69,7 +70,7 @@ To measure the impact of Quicklink on navigations:
 
 {% endmarkdownConvert %}
 
-<img class="article-image" src="/assets/images/screenshots/devtools-optimized-2.png" height="400px" width="800px">
+<img loading="lazy" class="article-image" src="/assets/images/screenshots/devtools-optimized-2.png" height="400px" width="800px">
 
 {% markdownConvert %}
 
@@ -108,7 +109,7 @@ The following table compares the main metrics obtained for each of the sites:
 
 {% endmarkdownConvert %}
 
-<img class="article-image" src="/assets/images/screenshots/wpt-metrics-comparison.png" height="105px" width="700px">
+<img loading="lazy" class="article-image" src="/assets/images/screenshots/wpt-metrics-comparison.png" height="105px" width="700px">
 
 {% markdownConvert %}
 
@@ -132,7 +133,7 @@ The unoptimized site starts rendering approximately at **2.5s**, the demo that u
 
 {% endmarkdownConvert %}
 
-<img class="article-image" src="/assets/images/screenshots/wpt-visual-comparison.png" height="430px" width="820px">
+<img loading="lazy" class="article-image" src="/assets/images/screenshots/wpt-visual-comparison.png" height="430px" width="820px">
 
 {% markdownConvert %}
 
@@ -142,7 +143,7 @@ A video can be generated from the [comparison page](https://www.webpagetest.org/
 
 {% endmarkdownConvert %}
 
-<img class="article-image" src="/assets/images/screenshots/wpt-video-comparison.gif" height="435px" width="600px">
+<img loading="lazy" class="article-image" src="/assets/images/screenshots/wpt-video-comparison.gif" height="435px" width="600px">
 
 {% markdownConvert %}