Examine source code of QuickTube Music

{
  "manifest_version": 2,
  "name": "QuickTube Music",
  "short_name": "QT Music",
  "version": "1.0",
  "permissions": [
    "*://music.youtube.com/*",
    "tabs"
  ],
  "description": "Quickly open YouTube Music on a pinned tab. Easy as *click*.",
  "author": "DaBluLite",
  "icons": {
    "48": "192.png",
    "128": "192.png"
  },
  "background": {
    "scripts": [
      "index.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "48": "192.png",
      "128": "192.png"
    },
    "default_title": "QuickTube Music"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "quicktube-music@aternifies.cf"
    }
  }
}