Elematter - modifications for this site

Original: https://github.com/jackrugile/elematter-js13k
Commit:   b7c4c0a9e06446a9afacbd605ea1efb0ae3433ae
Author:   Jack Rugile (MIT, see LICENSE.md - unchanged)

index.html is the author's prebuilt build/index.html with two small changes:
1. g.audio.play(): the promise returned by Audio.play() now has an empty catch
   handler, so a sound that the browser blocks before the first click (for example
   a hover sound) no longer raises an uncaught promise error. Sounds still only
   play when the browser allows them.
2. Added a short script at the end that scales the fixed 800x600 board (and its
   frame) with a CSS transform so it fits the embed frame.
Added THIRD-PARTY-NOTICES.txt with the Apache-2.0 notice of the bundled jsfxr
sound generator (removed from the built file by minification).
Game logic, graphics and sounds are unchanged. Unminified source:
https://github.com/jackrugile/elematter-js13k/tree/b7c4c0a9e06446a9afacbd605ea1efb0ae3433ae/src