NIU Mini Settings update and Refactor (#6651)

* update codebase to four-space indent

* update codebase to use #pragma once

* refactor config.h

* change info.json to debug linting

* refactor readme

- file header
- update docs links

* minimize and lint rules.mk

* change features

- enable mousekeys and nkro

* use GPIO commands for Status LED

Co-Authored-By: fauxpark <fauxpark@gmail.com>

* use IS_LED_ON macro

Co-Authored-By: fauxpark <fauxpark@gmail.com>

* update compile/flash examples in readme

* :flash doesn't use QMK Toolbox

keyboards/niu_mini/config.h

@@ -15,16 +15,15 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef CONFIG_H
-#define CONFIG_H
+#pragma once
 
 #include "config_common.h"
 
-#define DEVICE_VER 0x0001
 
 /* USB Device descriptor parameter */
 #define VENDOR_ID       0xFEED
 #define PRODUCT_ID      0x6060
+#define DEVICE_VER      0x0001
 #define MANUFACTURER    KBDFans
 #define PRODUCT         NIU Mini
 #define DESCRIPTION     A compact ortholinear keyboard
@@ -47,7 +46,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 /* number of backlight levels */
 #define BACKLIGHT_PIN B6
 #ifdef BACKLIGHT_PIN
-#define BACKLIGHT_LEVELS 4
+    #define BACKLIGHT_LEVELS 4
 #endif
 
 /* Set 0 if debouncing isn't needed */
@@ -61,11 +60,11 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #define RGB_DI_PIN E2
 #ifdef RGB_DI_PIN
-#define RGBLIGHT_ANIMATIONS
-#define RGBLED_NUM 14
-#define RGBLIGHT_HUE_STEP 8
-#define RGBLIGHT_SAT_STEP 8
-#define RGBLIGHT_VAL_STEP 8
+    #define RGBLIGHT_ANIMATIONS
+    #define RGBLED_NUM 14
+    #define RGBLIGHT_HUE_STEP 8
+    #define RGBLIGHT_SAT_STEP 8
+    #define RGBLIGHT_VAL_STEP 8
 #endif
 
 /*
@@ -85,5 +84,3 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //#define NO_ACTION_ONESHOT
 //#define NO_ACTION_MACRO
 //#define NO_ACTION_FUNCTION
-
-#endif