Examine source code of YouTube Quality Toggle

{
  "manifest_version": 2,
  "name": "YouTube Quality Toggle",
  "version": "1.0",
  "description": "Access the YouTube quality toggle all at once!",
  "permissions": [
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "commands": {
    "open-quality-settings": {
      "suggested_key": {
        "default": "Ctrl+Q"
      },
      "description": "Open YouTube Quality Settings"
    }
  },
  "icons": {
    "16": "icon_16.png",
    "48": "icon_48.png",
    "128": "icon_128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a6a347d9-1137-4ff8-ae5b-67dec709498c}"
    }
  }
}