add experimental branch url

config.js

@@ -40,7 +40,10 @@ var config = {
     '../gluon/beta/other/': 'beta',
     '../gluon/nightly/sysupgrade/': 'nightly',
     '../gluon/nightly/factory/': 'nightly',
-    '../gluon/nightly/other/': 'nightly'
+    '../gluon/nightly/other/': 'nightly',
+    '../gluon/experimental/sysupgrade/': 'experimental',
+    '../gluon/experimental/factory/': 'experimental',
+    '../gluon/experimental/other/': 'experimental'
   },
   // page title
   title: 'Firmware',