Fix docs typos

docs/docs/feature/underglow.md

@@ -21,7 +21,7 @@ Here you can see the RGB underglow feature in action using WS2812 LEDs.
 
 ## Enabling RGB Underglow
 
-To enable RGB underglow on your board or shield, simply enable the `ZMK_RGB_UNDERGLOW` and `CONFIG_X_STRIP` configuration values in the `.conf` file of your user config directory as such:
+To enable RGB underglow on your board or shield, simply enable the `ZMK_RGB_UNDERGLOW` and `X_STRIP` configuration values in the `.conf` file of your user config directory as such:
 
 ```
 CONFIG_ZMK_RGB_UNDERGLOW=y
@@ -116,7 +116,7 @@ Once you have your `led_strip` properly defined you need to add it to the root d
 };
 ```
 
-Finally you need to enable the `ZMK_RGB_UNDERGLOW` and `CONFIG_X_STRIP` STRIP configuration values in the `.conf` file of your board (or set a default in the `Kconfig.defconfig`):
+Finally you need to enable the `ZMK_RGB_UNDERGLOW` and `X_STRIP` configuration values in the `.conf` file of your board (or set a default in the `Kconfig.defconfig`):
 
 ```
 CONFIG_ZMK_RGB_UNDERGLOW=y