Examine source code of Night Owl - Dark Mode

{
  "manifest_version": 2,
  "name": "Night Owl - Dark Mode",
  "version": "3.1",
  "description": "Automatically enables dark mode for every website you visit.",
  "icons": {
    "48": "icon.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_title": "Toggle Dark Mode"
  },
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "nightowl@addon",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": [],
        "description": "This extension does not collect, store, or transmit any user data."
      }
    }
  }
}