* Previous version of multiple overrides of the default value of ZMK_USB
were problematic. Move to using board _defconfig files for the
defaults for those, along with proper `depends on` for ZMK_USB that
accounts for split and split roles.
* LV_ prefix from new LVGL official Kconfig now used.
* API changes for themes, container object removal, etc.
* Add our own Kconfig and code for theme default small font.
* Remove some hardcoded sizes.
* feat(nibble): add underglow support for nice_nano builds
* feat(nibble): add encoder to top, left most column to match standard assembly documentation
* refactor(nibble): add layer labels
* feat(nibble): add support for optional display ; off by default
* feat(nibble): add README
* fix(nibble): adjust oled rotation for easier reading
* fix(nibble): add additional note about enabling oled
* refactor(nibble): convert keymap to use tabs instead of spaces
* refactor(nibble): enable oled in dts/overlay by default
* refactor(nibble): cleanup alignment and formatting in nibble keymap
* refactor(nibble): re-align top most row of keymap to be sensible
* refactor(nibble): cleanup kscan map alignment
* refactor(nibble): indent first row of map/transform to properly align with physical columns
* fix(nibble): remove dangling code block from readme
Co-authored-by: KemoNine <mcrosson@kemonine.info>