[Keymap] Dactyl Manuform computer scientist's layout with split RGB enabled (#7519)

[Keymap] Dactyl Manuform computer scientist's layout with split RGB enabled (#7519)

* Added my Dactyl Manuform layout

* Added my Dactyl Manuform layout

* finalized key layout, added reset code, no LED yet

* finalized key layout, added reset code, no LED yet

* enabled RGB backlight

* enabled RGB backlight

* enabled RGB backlight

* supporting split rgb

* supporting split rgb

* supporting split rgb

* added media controls

* allowing ctrl/command to fallthrough from mouse layer so we can ctrl scroll to zoom in/out

* addressed PR comments, and make a couple last minute adjustments to the layout, to add in the Forwards Delete keycode

* decreased brightness even more