[Keyboard] Add Mixi (#9364)

* [Keyboard] Add Mixi

Co-authored-by: Ryan <fauxpark@gmail.com>

Co-authored-by: Ryan <fauxpark@gmail.com>

keyboards/mixi/mixi.c

@@ -0,0 +1,13 @@
+#include "mixi.h"
+
+void eeconfig_init_kb(void) {
+#ifdef RGBLIGHT_ENABLE
+    rgblight_enable(); // Enable RGB underglow by default
+#ifdef RGBLIGHT_ANIMATIONS
+    rgblight_mode(RGBLIGHT_MODE_TWINKLE + 5); // Set to RGB_TWINKLE animation by default
+#endif
+#endif
+
+    eeconfig_update_kb(0);
+    eeconfig_init_user();
+}