Examine source code of Page Dark Toggle

{
  "manifest_version": 2,
  "name": "Page Dark Toggle",
  "version": "1.0.0",
  "description": "Toggle dark mode on any page instantly.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Page Dark Toggle"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "darktoggle-e443791c-7c85-4c01-80b1-dafdbadb7aae@example.com",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}