fbopensource footer link

Author: leebyron

site/_core/Site.js

@@ -79,6 +79,9 @@ var Site = React.createClass({
                 <a>GitHub</a>
               </div>
             </section>
+            <a href="https://code.facebook.com/projects/" target="_blank" className="fbOpenSource">
+              <img src="/img/oss_logo.png" alt="Facebook Open Source" width="170" height="45" />
+            </a>
             <section className="copyright">
               Copyright &copy; 2016 Facebook Inc. The contents of this page are licensed BSD-3-Clause.
             </section>

site/_css/graphql.less

@@ -132,18 +132,14 @@ section {
 }
 
 footer {
-  .body-font(@size: 15px, @color: lighten(@dark-color, 40%));
+  .body-font(@size: 15px);
   background: lighten(@dark-color, 10%);
   box-shadow: inset 0 10px 10px -5px darken(@dark-color, 5%);
   padding-top: 2em;
   padding-bottom: 2em;
   -webkit-font-smoothing: antialiased;
   -moz-osx-font-smoothing: grayscale;
 
-  .copyright {
-    text-align: center;
-  }
-
   .sitemap {
     display: flex;
     justify-content: space-between;
@@ -176,6 +172,23 @@ footer {
       }
     }
   }
+
+  .fbOpenSource {
+    display: block;
+    margin: 1em auto;
+    opacity: 0.4;
+    transition: opacity 0.15s ease-in-out;
+    width: 170px;
+
+    &:hover {
+      opacity: 1.0;
+    }
+  }
+
+  .copyright {
+    color: rgba(255,255,255,0.4);
+    text-align: center;
+  }
 }
 
 h1 .anchor, h2 .anchor, h3 .anchor, h4 .anchor, h5 .anchor, h6 .anchor {