[Keyboard] Add support for Polaris (#8123)

* Drop in old files

* Make a blank template keyboard to refresh ancient files to latest config

* Update keymaps files to new format

* Remove chunks of config asked for removal in previous pullreqs

* Remove split pin option from config

* Update rules.mk to latest version

* Remove unused functions from polaris.c

* Add via keymap

* Build basic tsangan keymap; add QMK configurator info

* Remove temporary template

* Update keyboards/ai03/polaris/config.h

* Update keyboards/ai03/polaris/readme.md

* Update keyboards/ai03/polaris/readme.md

* Update keyboards/ai03/polaris/readme.md

* Update rules.mk

* Fixes as per pullreq

* Update keyboards/ai03/polaris/keymaps/default_ansi_tsangan/keymap.c

* Update keyboards/ai03/polaris/polaris.h

* Update keyboards/ai03/polaris/keymaps/default_ansi_tsangan/keymap.c

* Update keyboards/ai03/polaris/info.json

* Update keyboards/ai03/polaris/keymaps/testing/readme.md

keyboards/ai03/polaris/rules.mk

@@ -0,0 +1,32 @@
+# 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
+
+# Build Options
+#   change yes to no to disable
+#
+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 = yes        # 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
+RGBLIGHT_ENABLE = yes       # Enable keyboard RGB underglow
+MIDI_ENABLE = no            # MIDI support
+BLUETOOTH_ENABLE = no       # Enable Bluetooth with the Adafruit EZ-Key HID
+AUDIO_ENABLE = no           # Audio output on port C6
+FAUXCLICKY_ENABLE = no      # Use buzzer to emulate clicky switches
+HD44780_ENABLE = no         # Enable support for HD44780 based LCDs