[Keyboard] Add Phoebe, a keyboard by Maxr1998 (#6870)

* Add Phoebe, a keyboard by Maxr1998

* Improve include-guard

* Remove unused functions

* Remove unused extern

* Add image

* Some more fixes

keyboards/maxr1998/phoebe/rules.mk

@@ -0,0 +1,30 @@
+# MCU name
+MCU = atmega32u4
+
+# Bootloader
+#     This definition is optional, and if your keyboard supports multiple bootloaders of
+#     different sizes, comment this out, and the correct address will be loaded
+#     automatically (+60). See bootloader.mk for all options.
+BOOTLOADER = atmel-dfu
+
+# Build Options
+#   change to "no" to disable the options, or define them in the Makefile in
+#   the appropriate keymap folder that will get included automatically
+#
+BOOTMAGIC_ENABLE = no      # Virtual DIP switch configuration(+1000)
+MOUSEKEY_ENABLE = no       # Mouse keys(+4700)
+EXTRAKEY_ENABLE = no       # Audio control and System control(+450)
+CONSOLE_ENABLE = yes       # Console for debug(+400)
+COMMAND_ENABLE = no        # Commands for debug and configuration
+COMBO_ENABLE = no          # Key combo feature
+NKRO_ENABLE = yes          # Nkey Rollover - if this doesn't work, see here: https://github.com/tmk/tmk_keyboard/wiki/FAQ#nkro-doesnt-work
+BACKLIGHT_ENABLE = no      # Enable keyboard backlight functionality
+MIDI_ENABLE = no           # MIDI controls
+AUDIO_ENABLE = no          # Audio output on port C6
+UNICODE_ENABLE = no        # Unicode
+BLUETOOTH_ENABLE = no      # Enable Bluetooth with the Adafruit EZ-Key HID
+RGBLIGHT_ENABLE = yes      # Enable WS2812 RGB underlight.
+KEY_LOCK_ENABLE = yes
+API_SYSEX_ENABLE = no
+SLEEP_LED_ENABLE = no      # Breathing sleep LED during USB suspend
+