Add rainkeeb keyboard (#10875)

* Add rainkeeb

Add support for rainkeeb

* gpl license added

* updated

* Apply suggestions from code review

Co-authored-by: ridingqwerty <george.g.koenig@gmail.com>

* Apply suggestions from code review

Co-authored-by: ridingqwerty <george.g.koenig@gmail.com>

* Update info.json

* via keymap added

* updated keymap and .h to work properly

* fixed oled code oops

Co-authored-by: ridingqwerty <george.g.koenig@gmail.com>

keyboards/rainkeeb/rules.mk

@@ -0,0 +1,28 @@
+# MCU name
+MCU = atmega32u4
+
+# Bootloader selection
+BOOTLOADER = caterina
+
+# Build Options
+#   comment out to disable the options.
+#
+BOOTMAGIC_ENABLE = yes	# 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 = no      # Commands for debug and configuration
+SLEEP_LED_ENABLE = no    # Breathing sleep LED during USB suspend
+NKRO_ENABLE = yes		# USB 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
+AUDIO_ENABLE = no
+RGBLIGHT_ENABLE = no
+
+# OLED enable
+OLED_DRIVER_ENABLE = yes
+
+# Encoder enable
+ENCODER_ENABLE = yes
+
+# WPM counter enable
+WPM_ENABLE = yes