Broken link on the Preonic keyboard's README page

### Issue Description

[The first `qmk.fm` link](http://qmk.fm/preonic/) on the [Preonic's README page](https://github.com/qmk/qmk_firmware/blob/master/keyboards/preonic/readme.md) is broken (404).

The three other `qmk.fm` links redirect. I am not sure if that is intentional or not.