Updated dbroqua layout for HHKB keyboard (#1990)

Updated dbroqua layout for HHKB keyboard (#1990)

* - Fixed DK60 version in config.h

* - Updated dk60 readme with new QMK rules

* - Fixed wording in readme

* Added dbroqua layout for DZ60

I've also updated dz60.h to add "true HHKD" keymap definition (6U
spacebar).

With the default HHKB definition r_alt was not mapped and when I pressed
r_menu it was r_alt.

Regards

* Updated dbroqua layout for HHKB keyboard

Added default configuration and alternate (swap gui/alt keys).

Save user choice in keyboard memory (like plank, thanks for this
feature!).