Open source release under the MIT License.

Added

• MIT License. The engine may now be redistributed and modified.
• src/ — the unbundled sources.
• build.mjs — builds dist/retrotalk.js and dist/retrotalk.min.js from src/.
• test/ — tests that run without a browser (npm test).
• example/index.html — a minimal working page.
• The published page links to the API reference at its foot.

Changed

• The speech engine no longer carries the music engine with it. The bundle is
  about a fifth of the size it was.
• MmsxxRetroTalk is the only global the script defines.
• The AudioContext is now passed in by the caller:
  new MmsxxRetroTalk(new AudioContext()). It used to be created internally,
  which meant two of them on a page that already had audio.
• Functions that do not play anything are now on the class:
  MmsxxRetroTalk.renderTalk() and so on.

Removed

• The obfuscated build. There is nothing to hide in an open source release.
• The zip the site used to offer. The download points at the releases page.
• The breadcrumb on the published page. It named a manual the page is not
  part of, and neither the entry nor the neighbouring pages are published.
• The music engine's name from the version strip. That engine is not on this
  page; the strip names RetroTalk only.