(master): Add CDN reference & SRI to demo pages.

Author: Joe Crick

index.html

@@ -113,7 +113,17 @@ <h2 class="content-subhead">Installation</h2>
                         <a href="https://github.com/joe-crick/pure-css-components/blob/master/dist/pure-components.tar.gz?raw=true">download</a> it, or get it from a
                         CDN.
                     </p>
-                    
+
+<div style="background: #ffffff; overflow:auto;width:auto;border:solid gray;border-width:.1em .1em .1em .8em;padding:.2em .6em;"><pre style="margin: 0; line-height: 125%">
+&lt;link
+  rel=<span style="color: #a31515">&quot;stylesheet&quot;</span>
+  href=<span style="color: #a31515">&quot;https://unpkg.com/purecss-components@0.0.7/dist/pure-components.css&quot;</span>
+  integrity=<span style="color: #a31515">&quot;sha384-FfmMHw1nM6QpEpUtacs5k0pNzo88/JlQAevyYjewWTklEKxFsFyH2nbVdbX6xCf4&quot;</span>
+  crossorigin=<span style="color: #a31515">&quot;anonymous&quot;</span>&gt;
+</pre></div>
+
+
+
                     <div class="is-code-full">
                         <pre>yarn add pure<span>-</span>components</pre>
                     </div>