[Keyboard] Update COD67 support to complete it and add a personal map (#7291)

[Keyboard] Update COD67 support to complete it and add a personal map (#7291)

* Update docs for default keymap

* Update COD67 docs with fixes and macOS details

* Add a personal COD67 2-layer map with RGB control

* Enable RGB, NKRO and change firmware format to bin

* Swap k0D and k48 to fix backspace on the top row

* Add RGB config and tidy up a bit

* Finish default map because merlin was full of bbq

* Whoops, rogue tabs

* Typo fix in the main COD67 readme

* Remove empty function defs in keymap

* Swap how the backspace key relocation happens

* Fix PRODUCT_ID and add a link to software PWM docs

* Disable NKRO and bootmagic and enable mouse keys

* Better header guard

* Whoops, forgot to remote the #endif