Make list widget sortable

example/index.html

@@ -33,7 +33,7 @@
         content: '{"site_title": "CMS Demo"}'
       },
       "authors.yml": {
-        content: 'authors:\n  - name: Mathias\n    description: Co-founder @ Netlify\n'
+        content: 'authors:\n  - name: Mathias\n    description: Co-founder @ Netlify\n  - name: Chris\n    description: Co-founder @ Netlify\n'
       }
     }
   }