update index repo links

Author: yyx990803

themes/vue/layout/index.ejs

@@ -13,13 +13,13 @@
         <p class="desc">Vue.js is a library for building modern web interfaces. <br>It provides data-reactive components with a simple and flexible API.</p>
         <p class="buttons">
             <a href="/guide/installation.html" class="button">Install v<%- theme.vue_version %></a>
-            <a href="https://github.com/yyx990803/vue" target="_blank" class="button">Source on GitHub</a>
+            <a href="https://github.com/vuejs/vue" target="_blank" class="button">Source on GitHub</a>
         </p>
         <ul id="social">
             <li><a href="https://twitter.com/vuejs" class="twitter-follow-button" data-show-count="false" data-dnt="true">Follow @vuejs</a></li>
-            <li><iframe src="http://ghbtns.com/github-btn.html?user=yyx990803&repo=vue&type=watch&count=true"
+            <li><iframe src="http://ghbtns.com/github-btn.html?user=vuejs&repo=vue&type=watch&count=true"
         allowtransparency="true" frameborder="0" scrolling="0" width="100" height="20"></iframe></li>
-            <li class="last"><a href="https://gitter.im/yyx990803/vue" target="_blank"><img src="https://badges.gitter.im/Join%20Chat.svg"></a></li>
+            <li class="last"><a href="https://gitter.im/vuejs/vue" target="_blank"><img src="https://badges.gitter.im/Join%20Chat.svg"></a></li>
         </ul>
     </div>
     <div class="down"><img src="/images/down.png"></div>