embertemplatelint should run on gjs files as well (javascript.glimmer)

Current embertemplatelint only runs on handlebars (.hbs) files.

This is incomplete as gjs files also need this linting. I tried a PR here, but am a bit lost... specifically:

1. We only want to call this linter on `javascript.glimmer`, if I try to paste a copy/paste file into a javascript.glimmer directory in linters it does not run, only way I can get it to work is paste it into `javascript`
2. I would like to reuse the handlebars implementation, not sure how to share this code