Add edvorakjp keymap for the Helix (rev2) keyboard (#3340)

* add readme.md

* add extern declaration of edvorakjp_config to edvorakjp.h

* add oled.c

* add layout definitions

* add keymap.c

* add rules.mk

* fix rgblight issue: rgblight_setrgb() ignore RGBLIGHT_LIMIT_VAL

keyboards/helix/rev2/keymaps/edvorakjp/keymap_xrows.h

@@ -0,0 +1,28 @@
+#ifndef KEYMAP_XROWS_H
+#define KEYMAP_XROWS_H
+
+#include "edvorakjp.h"
+
+enum custom_keycodes {
+  KC_LOCK = NEW_SAFE_RANGE,
+};
+
+#define KC_ KC_TRNS
+
+#define KC_TMB1 LGUI_T(KC_TAB)
+#define KC_TMB2 LSFT_T(KC_SPC)
+#define KC_TMB3 LOWER // act as LOWER when hold, as KC_LANG2(=English) when tapped
+#define KC_TMB4 LCTL_T(KC_ESC)
+#define KC_TMB5 RSFT_T(KC_DEL)
+#define KC_TMB6 RAISE // act as RAISE when hold, as KC_LANG1(=Japanese) when tapped
+#define KC_TMB7 RCTL_T(KC_BSPC)
+#define KC_TMB8 RALT_T(KC_ENT)
+#define KC_TMB9 LGUI(KC_TAB)
+
+#define KC_RST  RESET
+#define KC_DBUG DEBUG
+#define KC_RTOG RGB_TOG
+#define KC_EDJP EDVORAK
+#define KC_QWER QWERTY
+
+#endif