Change to X macros for layer list

- Supports adding and removing layers from custom_config.h
- Add "U_" prefix to layer names
- Populate keymap from X macro
- Rename miryoku_alternatives.h to miryoku_layer_alternatives.h
- Rename miryoku_layer.h to miryoku_layer_selection.h
- Remove miryoku_layer_names.h
- Add miryoku_layer_list.h

miryoku/miryoku_babel/miryoku_layer_list.h

@@ -0,0 +1,32 @@
+// Copyright 2022 Manna Harbour
+// https://github.com/manna-harbour/miryoku
+// generated -*- buffer-read-only: t -*-
+
+#pragma once
+
+#if !defined (MIRYOKU_LAYER_LIST)
+
+#define MIRYOKU_LAYER_LIST \
+MIRYOKU_X(BASE,   "Base") \
+MIRYOKU_X(EXTRA,  "Extra") \
+MIRYOKU_X(TAP,    "Tap") \
+MIRYOKU_X(BUTTON, "Button") \
+MIRYOKU_X(NAV,    "Nav") \
+MIRYOKU_X(MOUSE,  "Mouse") \
+MIRYOKU_X(MEDIA,  "Media") \
+MIRYOKU_X(NUM,    "Num") \
+MIRYOKU_X(SYM,    "Sym") \
+MIRYOKU_X(FUN,    "Fun")
+
+#define U_BASE   0
+#define U_EXTRA  1
+#define U_TAP    2
+#define U_BUTTON 3
+#define U_NAV    4
+#define U_MOUSE  5
+#define U_MEDIA  6
+#define U_NUM    7
+#define U_SYM    8
+#define U_FUN    9
+
+#endif