Our original tab triggers are deprecated. You used to be able to type, for example, for [TAB KEY] in the JavaScript editor and it would expand into a for loop. They were a little buggy, a little opinionated, and a little deep in tech debt, so we ultimately canned them. Emmet tab triggers work though! They are only for HTML, but they are very cool. Try typing something like
header.main-header>nav>ul.site-nav>li*6>
a into the HTML editor then pressing TAB. We'd like to offer more customizable tab triggers one day, so feel free to send us your thoughts on that.