[Keyboard] _33 v2 (#9899)

* Initial prep for PR

* Fixing jsons for revs

* Remove old keymap ref in readme

* Add Rev1 default layout

* Fix extra comma in default r1 keymap

* Changed default keymap for r1 to match new split bottom row macro name, updated via keymap readme, updated r1 json to match layout macro name, updated split space macro for r1

* Moved combo configs to default keymaps, removed unused bootloader selections

* Update keyboards/underscore33/rev1/rules.mk

* Update keyboards/underscore33/rev2/rules.mk

* Refactor _33 folder structure

* Add VIA keymap to rev1

* Rename macros and product_id as suggested

keyboards/underscore33/rules.mk

@@ -1,25 +1 @@
-# MCU name
-MCU = atmega32u4
-
-# Bootloader selection
-#   Teensy       halfkay
-#   Pro Micro    caterina
-#   Atmel DFU    atmel-dfu
-#   LUFA DFU     lufa-dfu
-#   QMK DFU      qmk-dfu
-#   ATmega32A    bootloadHID
-#   ATmega328P   USBasp
-BOOTLOADER = atmel-dfu
-
-BOOTMAGIC_ENABLE = lite       # Virtual DIP switch configuration
-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
-# 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 = no       # Enable keyboard backlight functionality
-RGBLIGHT_ENABLE = no        # Enable keyboard RGB underglow
-TAP_DANCE_ENABLE = no
+DEFAULT_FOLDER = underscore33/rev1