Currently, the menu of the navbar is hard coded in the theme. We need to make the menu configurable. - [x] **Step 1.** Refer to <http://gohugo.io/extras/menus/>, we can config the menu in the `config.toml`. - [ ] **Step 2.** Refer to <http://gohugo.io/tutorials/create-a-multilingual-site/>, we can make the site support i18n.