handwired/qc60: refactor, Configurator update, and readme update (#4878)

handwired/qc60: refactor, Configurator update, and readme update (#4878)

* handwired/qc60: refactor and Configurator update

- correct layout macro name (LAYOUT_ANSI_DEFAULT to LAYOUT_ansi_default)
- add layout data for remaining layout macros
- correct ISO layout macros (neither had a split left Shift)
- refactor LAYOUT_iso_alt (place KC_NUHS key on home row; consistent with LAYOUT_iso_default)
- proto.h refactored to use #pragma once include guard

* handwired/qc60: keymap refactor

- delete redundant KC_TRNS and KC_NO aliases

* handwired/qc60: readme update

- update header (made consistent with QMK template)
- update Docs links (Newbs Guide; grammar)