Update links to docs sections.

Author: mrmrs

src/templates/nav_docs.html

@@ -32,10 +32,10 @@ <h2 class="f6 fw7 ttu tracked" id="layout">Layout</h2>
       </article>
       <article class="fn fl-ns w-100 w-25-l">
         <h2 class="f6 fw7 ttu tracked">Theming</h2>
-        <a class="f5 fw4 dim link mid-gray db pv1" href="themes/hovers/" title="Hovers">Hovers</a>
-        <a class="f5 fw4 dim link mid-gray db pv1" href="themes/background-size/" title="Background Size">Background Size</a>
-        <a class="f5 fw4 dim link mid-gray db pv1" href="themes/borders/" title="Borders">Borders</a>
-        <a class="f5 fw4 dim link mid-gray db pv1" href="themes/border-radius/" title="Border Radius">Border Radius</a>
+        <a class="f5 fw4 dim link mid-gray db pv1" href="/docs/themes/hovers/" title="Hovers">Hovers</a>
+        <a class="f5 fw4 dim link mid-gray db pv1" href="/docs/themes/background-size/" title="Background Size">Background Size</a>
+        <a class="f5 fw4 dim link mid-gray db pv1" href="/docs/themes/borders/" title="Borders">Borders</a>
+        <a class="f5 fw4 dim link mid-gray db pv1" href="/docs/themes/border-radius/" title="Border Radius">Border Radius</a>
       </article>
     </section>
   </section>