[Keyboard] Add handwired/floorboard (#7478)

[Keyboard] Add handwired/floorboard (#7478)

* added handwired/plonk

* Update readme.md

* Update readme.md

* Update info.json

* Update config.h

* Update readme.md

* Update keyboards/handwired/plonk/rules.mk

Co-Authored-By: fauxpark <fauxpark@gmail.com>
* Update rules.mk

* Update plonk.c

* Update plonk.h

* Update keymap.c

* Delete config.h

* Update keyboards/handwired/plonk/config.h

Co-Authored-By: fauxpark <fauxpark@gmail.com>
* Update rules.mk

* Update info.json

* Update keyboards/handwired/plonk/readme.md

Co-Authored-By: fauxpark <fauxpark@gmail.com>
* Update rules.mk

* Renamed the Plonk to the Floorboard. Another homage, just subtler this time.

* removed old plonk files

* Update config.h