Add Rart75 hotswap and support via (#16619)

* Add Keyboard Rart75 Hotswap version

* Update readme

* Update config and readme

* Update info.json

* update readme and keymaps

keyboards/rart/rart75hs/rules.mk

@@ -0,0 +1,22 @@
+# MCU name
+MCU = atmega32a
+
+# Bootloader selection
+BOOTLOADER = usbasploader
+
+# Processor frequency
+F_CPU = 16000000
+
+# Build Options
+#   change yes to no to disable
+#
+BOOTMAGIC_ENABLE = yes      # Enable Bootmagic Lite
+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
+NKRO_ENABLE = no            # Enable N-Key Rollover
+BACKLIGHT_ENABLE = no       # Enable keyboard backlight functionality
+RGBLIGHT_ENABLE = yes       # Enable keyboard RGB underglow
+AUDIO_ENABLE = no           # Audio output
+ENCODER_ENABLE = yes