Multiple frontend support (#110)

* Initial multiple frontend support

* Removed unnecessary require()

* Moved styles/images out of common

app/javascript/packs/common.js

@@ -1,9 +1,6 @@
 import { start } from 'rails-ujs';
 
-// import default stylesheet with variables
-require('font-awesome/css/font-awesome.css');
-require('mastodon-application-style');
-
-require.context('../images/', true);
+// import common styling
+require('../styles/common.scss');
 
 start();