qmk-firmware/keyboards/the_ruler
..
keymaps/default
config.h
info.json
readme.md
rules.mk
the_ruler.c
the_ruler.h

readme.md

The Ruler PCB

A custom keyboard PCB ruler, that can also function as a macro pad

Keyboard Maintainer: Maple Computing
Hardware Supported: PCB Ruler V1 by That-Canadian and Bishop Keyboards
Hardware Availability: https://www.maple-computing.com/products/pcb-ruler-v1-1

Make example for this keyboard (after setting up your build environment):

make the_ruler:default

See build environment setup then the make instructions for more information.