Adding a button to the top navigation menu

In order to create a button in the top navigation menu, do the following:

1. Create a new menu item in yur menu via Appearance>Menus.
2. Make sure that the "CSS classes" checkbox in the Screen Options dropdown is enabled.
   
3. Add classes btn btn-md-2 btn-primary in the "CSS Classes (optional)" field of your new menu item.
   
4. Save changes.