AMJ96 Refactor (#14571)

* clean up amj96.h

- use #pragma once include guard
- remove extra comments
- update matrix position alignment (easier readability)

* info.json: apply human-friendly formatting

* rename LAYOUT to LAYOUT_all

* clean up rules.mk

Align to QMK's AVR template.

* clean up default keymap

- use four-space indent
- add RESET keycode (Fn+R)
- remove unnecessary functions

* clean up config.h

- use #pragma once include guard
- move lighting settings to the middle of the file (QMK template conformance)
- remove Magic and MIDI configuration blocks

* update readme.md file

- update keyboard info list
- add flashing instructions
- update Docs links
- remove trailing spaces

* remove "empty" config.h and readme.md from default keymap

keyboards/amj96/rules.mk

@@ -17,8 +17,8 @@ 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 = no       # Enable keyboard backlight functionality
-RGBLIGHT_ENABLE = yes
-UNICODE_ENABLE = no         # Unicode
+RGBLIGHT_ENABLE = yes       # Enable keyboard RGB underglow
 AUDIO_ENABLE = no           # Audio output
+
 CUSTOM_MATRIX = yes
 SRC += matrix.c