[added] Twitter follow link to docs page footer

Author: mtscout6

Diff for: docs/src/PageFooter.js

@@ -9,10 +9,28 @@ const PageHeader = React.createClass({
             <div className='bs-docs-social'>
               <ul className='bs-docs-social-buttons'>
                 <li>
-                  <iframe className='github-btn' src={'http://ghbtns.com/github-btn.html?user=react-bootstrap&repo=react-bootstrap&type=watch&count=true'} width={95} height={20} title='Star on GitHub' />
+                  <iframe className='github-btn'
+                    src='http://ghbtns.com/github-btn.html?user=react-bootstrap&repo=react-bootstrap&type=watch&count=true'
+                    width={95}
+                    height={20}
+                    title='Star on GitHub' />
                 </li>
                 <li>
-                  <iframe className='github-btn' src={'http://ghbtns.com/github-btn.html?user=react-bootstrap&repo=react-bootstrap&type=fork&count=true'} width={92} height={20} title='Fork on GitHub' />
+                  <iframe className='github-btn'
+                    src='http://ghbtns.com/github-btn.html?user=react-bootstrap&repo=react-bootstrap&type=fork&count=true'
+                    width={92}
+                    height={20}
+                    title='Fork on GitHub' />
+                </li>
+                <li>
+                  <iframe
+                    src="http://platform.twitter.com/widgets/follow_button.html?screen_name=react_bootstrap&show_screen_name=true"
+                    width={230}
+                    height={20}
+                    allowTransparency="true"
+                    frameBorder='0'
+                    scrolling='no'>
+                  </iframe>
                 </li>
               </ul>
             </div>