Helix oled rgb compile sw (#2606)

* Helix keyboard OLED, RGBLIGHT enable/disable control integrate into rules.mk

rules.mk: add 4 Variables for compile control.

   # Helix keyboard customize
   # you can edit follows 4 Variables
   #  jp: 以下の4つの変数を必要に応じて編集します。
   OLED_ENABLE = no            # OLED_ENABLE
   LED_BACK_ENABLE = no        # LED backlight (Enable WS2812 RGB underlight.)
   LED_UNDERGLOW_ENABLE = no   # LED underglow (Enable WS2812 RGB underlight.)
   LED_ANIMATIONS = yes        # LED animations

config.h: auto set RGBLED_NUM by HELIX_ROWS and rules.mk's define

* HELIX_ROWS define move from config.h to rules.mk

* add readme.md

* rename readme.md to readme_jp.md

* add readme.md and modify readme_jp.md

keyboards/helix/rev2/keymaps/default/config.h

@@ -36,11 +36,14 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // #define EE_HANDS
 
 // Helix keyboard OLED support
-//#define SSD1306OLED
+//      see ./rules.mk: OLED_ENABLE=yes or no
+#ifdef OLED_ENABLE
+  #define SSD1306OLED
+#endif
 
 /* Select rows configuration */
 // Rows are 4 or 5
-#define HELIX_ROWS 5
+// #define HELIX_ROWS 5 see ./rules.mk
 
 /* key matrix size */
 // Rows are doubled-up
@@ -62,12 +65,19 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define TAPPING_FORCE_HOLD
 #define TAPPING_TERM 100
 
+// Helix keyboard RGB LED support
+//#define RGBLIGHT_ANIMATIONS : see ./rules.mk: LED_ANIMATIONS = yes or no
+//    see ./rules.mk: LED_BACK_ENABLE or LED_UNDERGLOW_ENABLE set yes
+#ifdef RGBLED_BACK
+  #if HELIX_ROWS == 4
+    #define RGBLED_NUM 25
+  #elif HELIX_ROWS == 5
+    #define RGBLED_NUM 32
+  #endif
+#else
+  #define RGBLED_NUM 6
+#endif
 
-#undef RGBLED_NUM
-#define RGBLIGHT_ANIMATIONS
-// Helix keyboard : see ./rules.mk: RGBLIGHT_ENABLE = yes or no
-// Helix keyboard : RGBLED_NUM 6 or 32
-#define RGBLED_NUM 6
 #if RGBLED_NUM <= 6
   #define RGBLIGHT_LIMIT_VAL 255
 #else