Keyboard: AMJ96 Refactor and Configurator update (#3707)

* AMJ96 Refactor

LAYOUT matrix and default keymap refactored to use full-length keycodes (instead of shorthand).

* Configurator update

Minor physical layout update and made the labels more sensible.

* Readme update

White space correction.

* Default keymap update: #include QMK_KEYBOARD_H

* rules.mk update

Disabled the following options as my local test compile's .hex ended up too big to fit in the available flash space:

MOUSEKEY_ENABLE
EXTRAKEY_ENABLE
BACKLIGHT_ENABLE
RGBLIGHT_ENABLE

If this is undesirable, suggestions are welcome.

* Config/rules update

Re-enabled MOUSEKEY_ENABLE, EXTRAKEY_ENABLE, BACKLIGHT_ENABLE, and RGBLIGHT_ENABLE and disabled COMMAND_ENABLE in rules.mk; enabled NO_ACTION_MACRO and NO_ACTION_FUNCTION per @drashna

* Swapped `___` for `XXX` in amj96.h per @mechmerlin

keyboards/amj96/rules.mk

@@ -55,12 +55,12 @@ BOOTMAGIC_ENABLE = no      # Virtual DIP switch configuration(+1000)
 MOUSEKEY_ENABLE = yes       # Mouse keys(+4700)
 EXTRAKEY_ENABLE = yes       # Audio control and System control(+450)
 CONSOLE_ENABLE = yes        # Console for debug(+400)
-COMMAND_ENABLE = yes        # Commands for debug and configuration
+COMMAND_ENABLE = no         # Commands for debug and configuration
 # Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
 SLEEP_LED_ENABLE = no       # Breathing sleep LED during USB suspend
 # if this doesn't work, see here: https://github.com/tmk/tmk_keyboard/wiki/FAQ#nkro-doesnt-work
 NKRO_ENABLE ?= yes          # USB Nkey Rollover
-# BACKLIGHT_ENABLE ?= yes     # Enable keyboard backlight functionality on B7 by default
+BACKLIGHT_ENABLE = yes      # Enable keyboard backlight functionality on B7 by default
 RGBLIGHT_ENABLE = yes
 MIDI_ENABLE = no            # MIDI support (+2400 to 4200, depending on config)
 UNICODE_ENABLE = no         # Unicode