Out of date CSS files?
In order to use some recently (and not-so-recently) added icons I tried rebuilding the font from git. I followed the "Build the font in a Docker container" steps from `README.md`.

The result looks good, for example the "ubuntu" icon is present in the built web fonts:

```
$ grep ubuntu fonts/forkawesome-webfont.svg
    <glyph glyph-name="ubuntu" unicode="&#xf36f;" horiz-adv-x="1280"
```

However no file under the `scss/` directory has been modified, and indeed no "ubuntu" icon there (`grep ubuntu scss/*` returns nothing). AIUI that's needed to enable the usage of icons with `<i>` tags.

Is there an extra step to rebuild the CSS files? If you have a pointer on what commands to run, I'll gladly create a PR to update the build instructions in the `README.md`.

Thanks!