Start misc battle documentation

include/constants/battle.h

@@ -306,4 +306,17 @@
 #define B_WAIT_TIME_MED   48
 #define B_WAIT_TIME_SHORT 32
 
+#define CASTFORM_NORMAL     0
+#define CASTFORM_FIRE       1
+#define CASTFORM_WATER      2
+#define CASTFORM_ICE        3
+#define NUM_CASTFORM_FORMS  4
+#define CASTFORM_SUBSTITUTE (1 << 7)
+
+#define FLEE_ITEM    1
+#define FLEE_ABILITY 2
+
+#define B_WIN_TYPE_NORMAL 0
+#define B_WIN_TYPE_ARENA  1
+
 #endif // GUARD_CONSTANTS_BATTLE_H

include/constants/battle_anim.h

@@ -318,7 +318,7 @@
 #define SOUND_PAN_TARGET    63
 
 // move background ids
-#define BG_DARK_ 0 // the same as BG_DARK but is unused
+#define BG_NONE 0 // the same as BG_DARK but is unused
 #define BG_DARK 1
 #define BG_GHOST 2
 #define BG_PSYCHIC 3