Examine source code of Dark Mode Toggle

{
  "manifest_version": 2,
  "name": "Dark Mode Toggle",
  "version": "1.0",
  "description": "Toggle dark mode on any website",
  "permissions": [
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "16": "icon-16.png",
      "32": "icon-32.png"
    },
    "default_title": "Toggle Dark Mode"
  },
  "content_scripts": [],
  "icons": {
    "16": "icon-16.png",
    "32": "icon-32.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{0b81866b-1bff-4a59-b7aa-80854d801fd8}"
    }
  }
}