feat(docs): Updating lighting config docs

docs/docs/config/backlight.md

@@ -0,0 +1,36 @@
+---
+title: Backlight Configuration
+sidebar_label: Backlight
+---
+
+See the [backlight feature page](/docs/features/backlight) for more details, including instructions for adding backlight support to a board.
+
+See [Configuration Overview](/docs/config) for instructions on how to change these settings.
+
+## Kconfig
+
+Definition file: [zmk/app/Kconfig](https://github.com/zmkfirmware/zmk/blob/main/app/Kconfig)
+
+| Option                               | Type | Description                                           | Default |
+| ------------------------------------ | ---- | ----------------------------------------------------- | ------- |
+| `CONFIG_ZMK_BACKLIGHT`               | bool | Enables LED backlight                                 | n       |
+| `CONFIG_ZMK_BACKLIGHT_BRT_STEP`      | int  | Brightness step in percent                            | 20      |
+| `CONFIG_ZMK_BACKLIGHT_BRT_START`     | int  | Default brightness in percent                         | 40      |
+| `CONFIG_ZMK_BACKLIGHT_ON_START`      | bool | Default backlight state                               | y       |
+| `CONFIG_ZMK_BACKLIGHT_AUTO_OFF_IDLE` | bool | Turn off backlight when keyboard goes into idle state | n       |
+| `CONFIG_ZMK_BACKLIGHT_AUTO_OFF_USB`  | bool | Turn off backlight when USB is disconnected           | n       |
+
+## Devicetree
+
+Applies to: [`/chosen` node](https://docs.zephyrproject.org/latest/build/dts/intro.html#aliases-and-chosen-nodes)
+
+| Property        | Type | Description                                  |
+| --------------- | ---- | -------------------------------------------- |
+| `zmk,backlight` | path | The node for the backlight LED driver to use |
+
+See the Zephyr devicetree bindings for LED drivers:
+
+- [gpio-leds](https://docs.zephyrproject.org/latest/build/dts/api/bindings/gpio/gpio-leds.html)
+- [pwm-leds](https://docs.zephyrproject.org/latest/build/dts/api/bindings/led/pwm-leds.html)
+
+See the [backlight feature page](/docs/features/backlight) for examples of the properties that must be set to enable backlighting.

docs/docs/config/underglow.md

@@ -5,11 +5,11 @@ sidebar_label: RGB Underglow
 
 See the [RGB Underglow feature page](/docs/features/underglow) for more details, including instructions for adding underglow support to a board.
 
-See [Configuration Overview](/docs/config/index) for instructions on how to change these settings.
+See [Configuration Overview](/docs/config) for instructions on how to change these settings.
 
 ## Kconfig
 
-RGB underglow depends on [Zephyr's LED strip driver](https://github.com/zephyrproject-rtos/zephyr/tree/master/drivers/led_strip), which provides additional Kconfig options.
+RGB underglow depends on [Zephyr's LED strip driver](https://github.com/zephyrproject-rtos/zephyr/tree/main/drivers/led_strip), which provides additional Kconfig options.
 
 Definition file: [zmk/app/Kconfig](https://github.com/zmkfirmware/zmk/blob/main/app/Kconfig)
 
@@ -38,6 +38,6 @@ Values for `CONFIG_ZMK_RGB_UNDERGLOW_EFF_START`:
 
 ## Devicetree
 
-ZMK does not have any Devicetree properties of its own. See the Devicetree bindings for [Zephyr's LED strip driver](https://github.com/zephyrproject-rtos/zephyr/tree/master/dts/bindings/led_strip).
+ZMK does not have any Devicetree properties of its own. See the Devicetree bindings for [Zephyr's LED strip drivers](https://github.com/zephyrproject-rtos/zephyr/tree/main/dts/bindings/led_strip).
 
 See the [RGB underglow feature page](/docs/features/underglow) for examples of the properties that must be set to enable underglow.

docs/sidebars.js

@@ -54,6 +54,7 @@ module.exports = {
     ],
     Configuration: [
       "config/index",
+      "config/backlight",
       "config/behaviors",
       "config/combos",
       "config/displays",