`versions.json` is the file that tells Nunjucks what version strings to append to client-side lolisafe assets (only crucial if you use [Cache-Control](#cache-control)).
`fontello.css` itself will use type 1, but its font files will use type 5.
Gulp will automatically append the version string into the built `fontello.css` in `dist` directory when running `yarn build` (or `dist-dev` when running `yarn develop`).
To bump type 5, you would have to run `yarn bump-versions 5`.
Version strings will NOT be used when `cacheControl` in `config.js` is not enabled, since they are only necessary when the assets are being cached indefinitely in browsers.