[index.html] Copy last paragraph from about-.html

… to provide a prominent link to the backing OBS-repo, see https://github.com/sailfishos-chum/sailfishos-chum.github.io/blob/master/chumweb/www/views/pages/about.html#L41-L44

chumweb/www/views/pages/index.html

@@ -12,6 +12,10 @@ <h1>Chum Web</h1>
         mobile operating system <a href="https://sailfishos.org/">Sailfish OS</a>, compiled for
         various hardware architectures and OS release versions.
     </p>
+    <p>
+        The SailfishOS:Chum repository is located at the
+        <a href="https://build.sailfishos.org/project/show/sailfishos:chum">the Sailfish OS OBS</a>.
+    </p>
 
     <section>
         <header><h2>Featured apps</h2></header>