Examine source code of Chess Speak

{
  "manifest_version": 2,
  "name": "Chess Speak",
  "version": "0.1",
  "description": "Speaks the chess notation as one makes a move",
  "icons": {},
  "content_scripts": [
    {
      "matches": [
        "*://*.lichess.org/*"
      ],
      "js": [
        "chessNotationSpeaker.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "sound/1.mp3",
    "sound/2.mp3",
    "sound/3.mp3",
    "sound/4.mp3",
    "sound/5.mp3",
    "sound/6.mp3",
    "sound/7.mp3",
    "sound/8.mp3",
    "sound/a.mp3",
    "sound/b.mp3",
    "sound/c.mp3",
    "sound/d.mp3",
    "sound/e.mp3",
    "sound/f.mp3",
    "sound/g.mp3",
    "sound/h.mp3",
    "sound/K.mp3",
    "sound/Q.mp3",
    "sound/N.mp3",
    "sound/R.mp3",
    "sound/B.mp3",
    "sound/x.mp3",
    "sound/+.mp3"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{24068ab6-efbd-49be-b54c-50659e2232b2}"
    }
  }
}