[Keyboard] Add Prime_EXL Plus to handwired (#8238)

* Add VIA support for Prime_L

* Update keyboards/primekb/prime_l/v1/config.h

* Add prime_exl_plus keyboard

* Temporary removal of prime_exl_plus

* Add Prime_EXL Plus, including VIA support

* Update keyboards/handwired/prime_exl_plus/readme.md

* Update keyboards/handwired/prime_exl_plus/readme.md

* Update keyboards/handwired/prime_exl_plus/readme.md

* Update keyboards/handwired/prime_exl_plus/rules.mk

* Update keyboards/handwired/prime_exl_plus/info.json

* Update keyboards/handwired/prime_exl_plus/info.json

* Update keyboards/handwired/prime_exl_plus/info.json

* Update keymap.c

* correct spacing of keymaps and layout macro. move indicator logic from user space to keyboard space

* further corrections to keymaps and layout macro.

* Update keyboards/handwired/prime_exl_plus/prime_exl_plus.c

* Update keyboards/handwired/prime_exl_plus/prime_exl_plus.c

* Update keyboards/handwired/prime_exl_plus/prime_exl_plus.c

* Update keyboards/handwired/prime_exl_plus/prime_exl_plus.c

* Update prime_exl_plus.c

* small edit to prime_exl_plus.c

keyboards/handwired/prime_exl_plus/rules.mk

@@ -0,0 +1,33 @@
+# 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 = no       # Virtual DIP switch configuration
+MOUSEKEY_ENABLE = no        # 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 = yes       # Enable keyboard RGB underglow
+MIDI_ENABLE = no            # MIDI support
+UNICODE_ENABLE = no         # Unicode
+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