Examine source code of darko mode

{
  "manifest_version": 3,
  "name": "darko mode",
  "description": "Toggle dark mode and light mode on any website",
  "version": "1.0.0",
  "icons": {
    "16": "/icons/icon-16.png",
    "32": "/icons/icon-32.png",
    "48": "/icons/icon-48.png",
    "128": "/icons/icon-128.png"
  },
  "author": "Darko Mode",
  "homepage_url": "https://darkomode.com",
  "permissions": [
    "storage",
    "activeTab",
    "tabs"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "/icons/icon-16.png",
      "32": "/icons/icon-32.png",
      "48": "/icons/icon-48.png",
      "128": "/icons/icon-128.png"
    },
    "default_title": "darko mode"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_start",
      "js": [
        "content-scripts/content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "darko-mode@darkomode.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}