Add twitter share button to index page.

docs/css/default.css

@@ -25,18 +25,29 @@ pre {
     margin-top: 9px;
 }
 
+body.index-page #main-content p.badges {
+  padding-bottom: 1px;
+}
+
 /* GitHub 'Star' badge */
-body.index-page #main-content iframe {
+body.index-page #main-content iframe.github-star-button {
     float: right;
     margin-top: -12px;
     margin-right: -15px;
 }
 
+/* Tweet button */
+body.index-page #main-content iframe.twitter-share-button {
+    float: right;
+    margin-top: -12px;
+    margin-right: 8px;
+}
+
 /* Travis CI badge */
-body.index-page #main-content p:first-of-type {
+body.index-page #main-content img.travis-build-image {
     float: right;
     margin-right: 8px;
-    margin-top: -14px;
+    margin-top: -9px;
     margin-bottom: 0px;
 }
 

docs/index.md

-<iframe src="http://ghbtns.com/github-btn.html?user=tomchristie&amp;repo=django-rest-framework&amp;type=watch&amp;count=true" allowtransparency="true" frameborder="0" scrolling="0" width="110px" height="20px"></iframe>
-[![Travis build image][travis-build-image]][travis]
+<p class="badges">
+<iframe src="http://ghbtns.com/github-btn.html?user=tomchristie&amp;repo=django-rest-framework&amp;type=watch&amp;count=true" class="github-star-button" allowtransparency="true" frameborder="0" scrolling="0" width="110px" height="20px"></iframe>
+
+<a href="https://twitter.com/share" class="twitter-share-button" data-url="django-rest-framework.org" data-text="Current status: Checking out the totally awesome Django REST framework! http://django-rest-framework.org" data-count="none">Tweet</a>
+<script>!function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="http://platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs");</script>
+
+<img alt="Travis build image" src="https://secure.travis-ci.org/tomchristie/django-rest-framework.png?branch=master" class="travis-build-image">
+</p>
 
 # Django REST framework