Improve docs for local dev

docs/_includes/footer.html

@@ -11,7 +11,7 @@
 
       <div class="footer-col footer-col-2">
         <ul class="social-media-list">
-          <li><a href="https://github.com/box/spout/issues"><span class="icon icon--github">{% include icon-github.svg %}</span><span class="username">GitHub Issues</span></a></li>
+          <li><a href="{{ site.github.issues_url }}"><span class="icon icon--github">{% include icon-github.svg %}</span><span class="username">GitHub Issues</span></a></li>
         </ul>
       </div>
 

docs/_includes/header.html

@@ -16,7 +16,7 @@
         <a class="page-link" href="{{ site.github.url }}/docs/">Documentation</a>
         <a class="page-link" href="{{ site.github.url }}/guides/">Guides</a>
         <a class="page-link" href="{{ site.github.url }}/faq/">FAQ</a>
-        <a class="page-link" href="https://github.com/box/spout">
+        <a class="page-link" href="{{ site.github.repository_url }}">
             <span class="icon icon--github">{% include icon-github.svg %}</span>
             <span class="username">GitHub</span>
         </a>