Add installation instruction

README.md

@@ -2,3 +2,22 @@ user_wcf
 ========
 
 Owncloud user backend for the Woltlab Community Framework (WCF) used by Woltlab Burning Board (WBB3)
+
+To use this backend you need to enable the app in OwnCloud and then add the user backend to your configuration file:
+
+```php
+$CONFIG = array (
+  // [...]
+  'user_backends' => array (
+    array (
+      'class' => 'OCA\\User_WCF\\User_WCF',
+      'arguments' => array (
+        // Change to your WCF path containing the DB settings (config.inc.php)
+        '/var/www/forum/wcf',
+        // Change this to the WCF groups that should be allowed to use OC.
+        array ('Admins', 'Privilged Users', 'Some other Privileged Group'),
+      ),
+    ),
+  ),
+);
+```