Examine source code of Bookmark Music Player

{

  "manifest_version": 2,
  "name": "BookmarkPlayer",
  "version": "1.4",

  "description": "This add-on creates a 'BookmarkPlayer' folder in a bookmark.\nIf you put the corresponding URL or folder in this, you can play it continuously from the toolbar.\n\nCorresponding URL:\nhttps://www.nicovideo.jp/watch/smxxxxxxxx\nhttps://www.youtube.com/watch?v=xxxxxxxxxxxx\nhttps://soundcloud.com/Artist name/Song name\n\nAllow autoplay to these sites from the firefox Settings > Privacy and Security > Allow settings.\n\nSetup support&Requests&Bugs, etc.\n  SHiii0410223@gmail.com",
  "permissions": [
    //"notifications",
    "tabs",
    // "storage",
    "<all_urls>",
    "bookmarks"
  ],

  "background": {
    "scripts": [ "background.js" ]
  },
  "icons": {
    "16": "image/icon_enable16.png",
    "32": "image/icon_enable32.png",
    "64": "image/icon_enable64.png"
  },

  "options_ui": {
    "page": "options/options.html"
  },
  "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self';",

  "browser_action": {
    // "browser_style": true,
    "default_icon": {
      "16": "image/icon_disable16.png",
      "32": "image/icon_disable32.png",
      "64": "image/icon_disable64.png"
    },
    "default_popup": "popup/popup.html"
  }
}