feat: Add `studio` as a feature option in metadata

* Allow boards/shields to indicate ZMK Studio support in the `features` list.

docs/docs/development/hardware-integration/hardware-metadata-files.md

@@ -95,6 +95,7 @@ Boards and shields should document the sets of hardware features found on them u
 - `encoder` - Indicates the hardware contains one or more rotary encoders.
 - `underglow` - Indicates the hardware includes underglow LEDs.
 - `backlight` - Indicates the hardware includes backlight LEDs.
+- `studio` - Indicates the keyboard is ready to use with [ZMK Studio](../../features/studio.md).
 - `pointer` (future) - Used to indicate the hardware includes one or more pointer inputs, e.g. joystick, touchpad, or trackpoint.
 
 ### Siblings

schema/hardware-metadata.schema.json

@@ -57,7 +57,8 @@
           "encoder",
           "underglow",
           "backlight",
-          "pointer"
+          "pointer",
+          "studio"
         ]
       }
     },