abcjs player mod MV2 ਵਲੋਂ DaveRo

Adds buttons to https://editor.drawthedots.com/ to add playback options.
Suppress guitar chords, individual voices, and repeats. Each of these can be turned on or off.

It also works on http://michaeleskin.com/abc

Note:
This is a MV2 (Manifest Version 2) copy of this addon:
https://addons.mozilla.org/en-GB/firefox/addon/abcjs-player-mod/

The MV2 version is only required for Android because there is a bug (1841438) in Firefox for Android which is - temporarily I hope - preventing the MV3 version from running. Once that is fixed this version will be deleted.