RGB underglow support for JJ40, clean up redundant code in Mechmini keymap (#2196)

* Cleanup Mechmini keymap. Once the custom RGB function is defined, there is no need to manually handle RGB code.

* Change default to KEYMAP_MIT, not KEYMAP_OFFSET

* Add custom RGB code for JJ40

* Reset Mechmini advertised power draw to 500. Will have to test actual maximum power draw later.

* RGB working on JJ40.

* Fix: saturation increase/decrease flipped

* Add new directory for my custom keymap with RGB keycodes

* Swap LAlt and LGUI

* Update JJ40 max power draw with measured value

* Update: fun40 rules.mk to enable underglow; earlier failed Travis CI

keyboards/jj40/rules.mk

@@ -26,7 +26,7 @@ F_CPU = 12000000
 
 # Bootloader
 #     This definition is optional, and if your keyboard supports multiple bootloaders of
-#     different sizes, comment this out, and the correct address will be loaded 
+#     different sizes, comment this out, and the correct address will be loaded
 #     automatically (+60). See bootloader.mk for all options.
 BOOTLOADER = bootloadHID
 
@@ -37,8 +37,11 @@ EXTRAKEY_ENABLE = yes
 CONSOLE_ENABLE = no
 COMMAND_ENABLE = yes
 BACKLIGHT_ENABLE = no
-RGBLIGHT_ENABLE = no
-RGBLIGHT_CUSTOM_DRIVER = no
+
+RGBLIGHT_ENABLE = yes
+RGBLIGHT_CUSTOM_DRIVER = yes
+DISABLE_WS2812 = yes  # TODO check if this is necessary
+
 KEY_LOCK_ENABLE = yes
 
 # Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE