main menu Dropdown support without installing a module

Hi Everyone,

I'd like to add child items to the main menu at www.tambourhinoceros.net. At the moment there's a /links child item to the 'about' item. I've set the menu as source for both primary and secondary links at /admin/structure/menu/settings.

Since I don't want any animations and unnecessary markup I'd like to just add some code to my template instead of using nicemenus or similar. Can anybody guide me in the right direction?