Adding "fork me on github" banner

docs/layouts/chrome/footer.html

@@ -1,5 +1,8 @@
         </div>
       </div>
+      <div id="ribbon">
+          <a href="http://github.com/spf13/hugo" rel="me">Fork me on GitHub</a>
+      </div>
       <hr>
       <footer id="footer">
             <p class="pull-right"><a href="#top">Back to top</a></p>

docs/static/static/css/bootstrap-responsive.css

@@ -1106,4 +1106,27 @@
     height: auto !important;
     overflow: visible !important;
   }
-}
+}
+
+#ribbon {
+    background-color: #a00;
+    overflow: hidden;
+    position: absolute;
+    right: -3em;
+    top: 2.5em;
+    -moz-transform: rotate(45deg);
+    -webkit-transform: rotate(45deg);
+    -moz-box-shadow: 0 0 1em #888;
+    -webkit-box-shadow: 0 0 1em #888;
+}
+#ribbon a {
+    border: 1px solid #faa;
+    color: #fff;
+    display: block;
+    font: bold 81.25% "Helvetiva Neue",Helvetica,Arial,sans-serif;
+    margin: 0.05em 0 0.075em 0;
+    padding: 0.5em 3.5em;
+    text-align: center;
+    text-decoration: none;
+    text-shadow: 0 0 0.5em #444;
+}