This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
`.js.no-module.es6` files will be transpiled without producing a module.
import/export statements are deliberately not supported, so one would still need to use
`const module = require('moduleName').default.`
