Update joystick config binding

Fix off-by-one error.

src/packages/game/input/IZ_joystick.c

@@ -1,6 +1,6 @@
 #include "IZ_joystick.h"
 
-static INI_ConfigItem joystick_config_items[IZ_PLAYERS * (IZ_CONTROLS - 4 + 2) + 1];
+static INI_ConfigItem joystick_config_items[IZ_PLAYERS * (IZ_CONTROLS - 4 + 3) + 1];
 
 bool IZ_JoystickIsValidAxisThreshold(u16 value) {
 	return (4000 <= value && value <= 12000);
@@ -202,7 +202,8 @@ void IZ_JoystickInitializeConfigItems(INI_ConfigItem config_items[]) {
 	for (player_index = 0; player_index < IZ_PLAYERS; player_index += 1) {
 		main_section_name = IZ_calloc(64, sizeof(char));
 		sprintf(main_section_name, "Joystick.%d", player_index);
-		u8 base_index = (player_index * (IZ_CONTROLS - 4 + 2));
+		// The `+ 3` corresponds to the first three config items. Add as appropriate.
+		u8 base_index = (player_index * (IZ_CONTROLS - 4 + 3));
 		config_items[base_index] = (INI_ConfigItem) {
 			INI_CONFIG_TYPE_I32,
 			main_section_name,
@@ -254,7 +255,7 @@ void IZ_JoystickInitializeConfigItems(INI_ConfigItem config_items[]) {
 		}
 	}
 
-	config_items[IZ_PLAYERS * (IZ_CONTROLS - 4 + 2) + 1] = INI_CONFIG_ITEM_NULL;
+	config_items[IZ_PLAYERS * (IZ_CONTROLS - 4 + 3)] = INI_CONFIG_ITEM_NULL;
 }
 
 IZ_ProcedureResult IZ_JoystickInitializeConfig(IZ_JoystickState(* state)[IZ_PLAYERS], const char* config_path, u8 argc, const char* argv[]) {