Nix Studio OXALYS80 Refactor (#14473)

* update grid alignment of keycodes

* update key assignments on via keymap

A seemingly-misplaced key assignment on Layers 1 through 3 of the via keymap led to keys being off by one in comparison to the default keymap.

* switch Backslash and Backspace on via keymap base layer

Matches the via keymap's key mapping to that of the default keymap.

* use QMK 3-character notation in oxalys80.h

* add matrix diagram; remove Planck reference

* add LAYOUT_tkl_ansi and LAYOUT_tkl_ansi_wkl layout macros

* add LAYOUT_tkl_ansi_tsangan macro

* add ISO layouts

Add LAYOUT_tkl_iso, LAYOUT_tkl_iso_tsangan, and LAYOUT_tkl_iso_wkl macros.

* enable Community Layouts support

* tidy up rules.mk

* readme tidy-up

keyboards/nix_studio/oxalys80/rules.mk

@@ -10,14 +10,16 @@ BOOTLOADER = atmel-dfu
 BOOTMAGIC_ENABLE = lite     # Enable Bootmagic Lite
 MOUSEKEY_ENABLE = yes       # Mouse keys
 EXTRAKEY_ENABLE = yes       # Audio control and System control
-CONSOLE_ENABLE = no        # Console for debug
-COMMAND_ENABLE = no        # Commands for debug and configuration
+CONSOLE_ENABLE = no         # Console for debug
+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 = no            # USB Nkey Rollover
-BACKLIGHT_ENABLE = yes      # Enable keyboard backlight functionality on B7 by default
+BACKLIGHT_ENABLE = yes      # Enable keyboard backlight functionality
 RGBLIGHT_ENABLE = yes       # Enable RGB underglow
-UNICODE_ENABLE = no         # Unicode
+BLUETOOTH_ENABLE = no       # Enable Bluetooth
 AUDIO_ENABLE = no           # Audio output
 LTO_ENABLE = yes
+
+LAYOUTS = tkl_ansi tkl_iso