From https://harfangk.github.io/2016/10/02/using-emmet-to-type-erb-or-eex-tags.html
{ "eelixir": { "extends": "html", "snippets": { "eex": "<%= | %>\n\t${child}<% end %>" } }, "eruby": { "extends": "html", "snippets": { "erb": "<%= | %>\n\t${child}<% end %>" } } }