Examine source code of YouTube Dark Mode

{
  "action": {
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "worker.js"
    ]
  },
  "content_scripts": [
    {
      "all_frames": true,
      "js": [
        "data/inject.js"
      ],
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_start"
    }
  ],
  "default_locale": "en",
  "description": "__MSG_appDesc__",
  "host_permissions": [
    "https://*/*"
  ],
  "icons": {
    "16": "data/icons/16.png",
    "32": "data/icons/32.png",
    "48": "data/icons/48.png",
    "64": "data/icons/64.png",
    "128": "data/icons/128.png",
    "256": "data/icons/256.png",
    "512": "data/icons/512.png"
  },
  "manifest_version": 3,
  "name": "__MSG_appName__",
  "permissions": [
    "storage",
    "cookies",
    "declarativeNetRequest"
  ],
  "version": "2.5",
  "browser_specific_settings": {
    "gecko": {
      "id": "{74ac956e-8e54-4d83-b89e-03ebae7dc6d1}",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "declarative_net_request": {
    "rule_resources": [
      {
        "id": "youtubedarkmode",
        "enabled": true,
        "path": "youtubedarkmode.json"
      }
    ]
  },
  "web_accessible_resources": [
    {
      "matches": [
        "<all_urls>"
      ],
      "resources": [
        "data/icons/disabled/32.png"
      ]
    }
  ]
}