[Keyboard] Add KBD67 Hotswap Support (#4916)

* initial commit

* move the original kbd67 stuff into its own directory, rev1

* get rid of vanilla cookie cutter code

* put in the switch matrix pins, backlight pin, and rgb underglow pin. Number of underglow LEDs is questionable.

* switch matrix created for hotswap

* create a basic keymap for testing

* make info.json for QMK Configurator support

* rename kbd67 due to compile error

* kbd67 generic readme file

* fix make instructions for the new rev1

* comment out unneeded rgb light #defines

* Update keyboards/kbd67/readme.md

Add an extra space for proper markdown rendering

Co-Authored-By: mechmerlin <30334081+mechmerlin@users.noreply.github.com>

* Update keyboards/kbd67/hotswap/hotswap.h

Co-Authored-By: mechmerlin <30334081+mechmerlin@users.noreply.github.com>

* Update keyboards/kbd67/hotswap/keymaps/default/keymap.c

Co-Authored-By: mechmerlin <30334081+mechmerlin@users.noreply.github.com>

* use pragma once

* proper format of MechMerlin

keyboards/kbd67/rev1/keymaps/default/readme.md

@@ -0,0 +1 @@
+# The default keymap for kbd67