[Core] Caps Word "Invert on shift" option: pressing Shift inverts the shift state. (#20092)

Co-authored-by: Nick Brassel <[email protected]>

data/schemas/keyboard.jsonschema

@@ -227,7 +227,8 @@
                 "enabled": {"type": "boolean"},
                 "both_shifts_turns_on": {"type": "boolean"},
                 "double_tap_shift_turns_on": {"type": "boolean"},
-                "idle_timeout": {"$ref": "qmk.definitions.v1#/unsigned_int"}
+                "idle_timeout": {"$ref": "qmk.definitions.v1#/unsigned_int"},
+                "invert_on_shift": {"type": "boolean"}
             }
         },
         "combo": {