Television Simulator video-game engine

This repo contains the video-game engine, split out from Television Simulator as an IFrame engine. This is a very thin wrapper over Nostalgist.js with the following characteristics:

• Inputs are limited to controllers only. Plug in an Xbox controller for the best experience.
• No games will load until we're told what options to load via the TVS IFrame API.
• State is saved automatically to Indexed DB when the page is unloaded (signaled by the Tvs.Terminate event)

Use within TVS:

- number: -1
      iframe:
        src: http://gcpw.art/tvs/engines/video-game # replace with your own server if self-hosting
        options:
          game: flappybird.nes # Required. The game library by default is from `retrobrews.github.io`. You can specify a game from there directly. Set to false to use a core that doesn't require a game.
          core: fceumm # Required. The system to emulate. BREAKING CHANGE since v5.0.0: Core is required and older `console` option is removed.
          # The video game engine doesn't support granular volume adjustment right now, but mute and unmute work.
          # BREAKING CHANGE since v6.0.0: Only game controller inputs are accepted to free up reserved keyboard keys for future use.