Implement audio engine; add music for scenes, events, landmarks; add action sound effects

[orsi]

Large feature addition to the game!

Implemented a rudimentary Audio engine that utilized the Web Audio API in order to load, play, fade, and transition audio between scenes, events, and actions.

I've included over 40 audio files which cover:

• BG music for Room, Outside, Path, Ship, and Space areas
• BG music for the World
• Leitmotifs for every random event, landmark, and each encounter tier
• Sound effects for most action categories, weapon types, asteroid hits, world death, etc.
• A final ending piece!

Any and all feedback appreciated.

Jon

[orsi]

In addition, I've added to the UI menu at the bottom the option to turn sound on/off, similar to how the light on/off button works.

[Continuities]

Merged in a601473645cd58a7f51c382d68fc918472f1dcf1 Thanks so much @orsi