[Keymap] update @nstickney's keymaps (#6076)

[Keymap] update @nstickney's keymaps (#6076)

* [Keymap] iris@nstickney: improve RGB init

Perfecting the rgb backlight initialization with a delay for each
color; also start and stop the animation at the "default layer"
color.

* [Keymap] iris,ergodox@nstickney fix FN on SYMB

The function key was not operational on the SYMB and SYSH layers due
to other keycodes being mapped over MO() on those layers. The
offending keycodes have been moved to other keys.

* [Keymap] add @nstickney's userspace

Pulled common code out to a userspace directory for my iris and
ergodox keymaps.

* [Keymap] iris@nstickney add image to README

Added an image from keyboard-layout-editor.com to meet the README
standard.

* iris@nstickney hue values now `uint8_t` (#6050)