Add new mountain background

src/arena.ts

@@ -331,6 +331,7 @@ export function getBiomeHasProps(biomeType: Biome): boolean {
     case Biome.BEACH:
     case Biome.LAKE:
     case Biome.SEABED:
+    case Biome.MOUNTAIN:
     case Biome.BADLANDS:
     case Biome.CAVE:
     case Biome.DESERT:

src/battle-phases.ts

@@ -242,7 +242,7 @@ export class EncounterPhase extends BattlePhase {
 
   doEncounter() {
     if (startingWave > 10) {
-      for (let m = 0; m < Math.floor(startingWave / 10); m++)
+      for (let m = 0; m < Math.min(Math.floor(startingWave / 10), 99); m++)
         this.scene.addModifier(getPlayerModifierTypeOptionsForWave((m + 1) * 10, 1, this.scene.getParty())[0].type.newModifier());
     }
 

src/battle-scene.ts

@@ -2,7 +2,7 @@ import Phaser from 'phaser';
 import { Biome } from './data/biome';
 import UI from './ui/ui';
 import { EncounterPhase, SummonPhase, NextEncounterPhase, NewBiomeEncounterPhase, SelectBiomePhase, MessagePhase, CheckLoadPhase, TurnInitPhase, ReturnPhase, ToggleDoublePositionPhase, CheckSwitchPhase } from './battle-phases';
-import Pokemon, { PlayerPokemon, EnemyPokemon, FieldPosition } from './pokemon';
+import Pokemon, { PlayerPokemon, EnemyPokemon } from './pokemon';
 import PokemonSpecies, { allSpecies, getPokemonSpecies, initSpecies } from './data/pokemon-species';
 import * as Utils from './utils';
 import { Modifier, ModifierBar, ConsumablePokemonModifier, ConsumableModifier, PokemonHpRestoreModifier, HealingBoosterModifier, PersistentModifier, PokemonHeldItemModifier, ModifierPredicate } from './modifier/modifier';