[Keyboard] Sol 3 Keyboard from RGBKB (#15687)

Co-authored-by: Ryan <fauxpark@gmail.com>
Co-authored-by: Franklyn Tackitt <franklyn@tackitt.net>

keyboards/rgbkb/sol3/rules.mk

@@ -0,0 +1,49 @@
+# MCU name
+MCU = STM32F303
+
+# Bootloader selection
+BOOTLOADER = stm32-dfu
+
+# Touch encoder needs
+SRC += ../common/touch_encoder.c
+SRC += ../common/common_oled.c
+QUANTUM_LIB_SRC += i2c_master.c
+
+# Build Options
+#   change yes to no to disable
+#
+BOOTMAGIC_ENABLE = yes      # Enable Bootmagic Lite
+MOUSEKEY_ENABLE = no        # Mouse keys
+EXTRAKEY_ENABLE = yes       # Audio control and System control
+CONSOLE_ENABLE = yes        # Console for debug
+COMMAND_ENABLE = no         # Commands for debug and configuration
+NKRO_ENABLE = yes           # Enable N-Key Rollover
+AUDIO_ENABLE = yes          # Audio output
+AUDIO_DRIVER = dac_additive
+
+DYNAMIC_MACRO_ENABLE = yes
+DIP_SWITCH_ENABLE = yes
+
+WS2812_DRIVER = pwm
+RGBLIGHT_ENABLE = no
+RGB_MATRIX_ENABLE = yes
+RGB_MATRIX_DRIVER = WS2812
+
+OLED_ENABLE = yes
+OLED_DRIVER = SSD1306    # Enable the OLED Driver
+
+ENCODER_ENABLE = yes
+
+SPLIT_KEYBOARD = yes
+SERIAL_DRIVER = usart
+LTO_ENABLE = yes
+OPT = 3
+
+OPT_DEFS += -DOLED_FONT_H=\"../common/glcdfont.c\"
+OPT_DEFS += -Ikeyboards/rgbkb/common
+
+# TODO: Implement fast matrix scanning
+# matrix optimisations
+# SRC += matrix.c
+
+DEFAULT_FOLDER = rgbkb/sol3/rev1