update README.md

Author: cploutarchou

README.md

@@ -4,7 +4,16 @@
 * Upload project on server
 * Rename database_conf.php file to database.php
 * Execute or import code from /database/menumanager.sql file with sample data
-
+* Update Menu Using Menu manager
+* Use get_menu() function to  get menu on UI .
+* Note : get_menu() function need 2 parameters:
+    1. Menu ID 
+    2. Class name (You can use black css class if you need black navbar)
+ 
+```php 
+ <?php get_menu('1', ''); ?> for default navbar
+ <?php get_menu('1', 'black'); ?> for black navbar
+```
 **Menu Manager Screenshots**
 
 ![alt text](https://github.com/cploutarchou/codeIgniter-menu-manager/blob/master/assets/forReadme/screenshot-ci-menu-manager.christosploutarchou.com-2020.01.png "Logo Title Text 1")