[Audio] Replace Title BGM with custom BGM by Firel (#5189)

* Replace Title BGM with custom BGM by Firel

Also added descriptions for the battle scene and arena's getBgmLoopPoint methods.

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Co-authored-by: damocleas <damocleas25@gmail.com>

src/battle-scene.ts

@@ -2084,8 +2084,11 @@ export default class BattleScene extends SceneBase {
     return sound;
   }
 
+  /** The loop point of any given battle, mystery encounter, or title track, read as seconds and milliseconds. */
   getBgmLoopPoint(bgmName: string): number {
     switch (bgmName) {
+      case "title": //Firel PokéRogue Title
+        return 46.500;
       case "battle_kanto_champion": //B2W2 Kanto Champion Battle
         return 13.950;
       case "battle_johto_champion": //B2W2 Johto Champion Battle

src/field/arena.ts

@@ -695,6 +695,7 @@ export class Arena {
     globalScene.loadBgm(this.bgm);
   }
 
+  /** The loop point of any given biome track, read as seconds and milliseconds. */
   getBgmLoopPoint(): number {
     switch (this.biomeType) {
       case Biome.TOWN: