Its purpose is to let users choose a Config language by clicking on its corresponding tab. Upon doing so, every Code toggler on the page will be switched to the target language. Also, target language will be saved in user's `localStorage` so when they go to a different pages, Code Toggler display their last "toggled" config language.
The `code-toggler` shortcode is not an internal Hugo shortcode. This page's purpose is to test out a custom feature that we use throughout this site. See: https://github.com/gohugoio/gohugoioTheme/blob/master/layouts/shortcodes/code-toggle.html