Examine source code of 500% Volume Booster

{
  "manifest_version": 2,
  "name": "Volume Booster",
  "version": "1.1.2",
  "description": "Boost webpage audio and video volume beyond 100% using the Web Audio API.",
  "browser_specific_settings": {
    "gecko": {
      "id": "volume-booster@local",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "<all_urls>",
    "activeTab",
    "tabs",
    "storage"
  ],
  "icons": {
    "48": "icon.svg",
    "96": "icon.svg"
  },
  "browser_action": {
    "default_title": "Volume Booster",
    "default_popup": "popup.html",
    "default_icon": {
      "32": "icon.svg"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}