Examine source code of YouTube HD Quality Settings

{
  "manifest_version": 3,
  "name": "YouTube HD Quality Settings",
  "version": "1.0.2",
  "description": "Automatically set your preferred YouTube video quality and premium codec preferences, with an optional automatic Theater Mode switch on desktop YouTube pages.",
  "permissions": [
    "storage",
    "webNavigation"
  ],
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'"
  },
  "host_permissions": [
    "*://www.youtube.com/*",
    "*://m.youtube.com/*",
    "*://music.youtube.com/*"
  ],
  "background": {
    "scripts": [
      "common/config.js",
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/*",
        "*://m.youtube.com/*",
        "*://music.youtube.com/*"
      ],
      "js": [
        "common/config.js",
        "content/bridge.js"
      ],
      "run_at": "document_start",
      "world": "MAIN"
    },
    {
      "matches": [
        "*://www.youtube.com/*",
        "*://m.youtube.com/*",
        "*://music.youtube.com/*"
      ],
      "js": [
        "common/config.js",
        "content/isolated.js"
      ],
      "run_at": "document_idle",
      "world": "ISOLATED"
    }
  ],
  "action": {
    "default_popup": "popup/popup.html",
    "default_icon": {
      "48": "icons/icon-48.png",
      "96": "icons/icon-96.png"
    }
  },
  "options_ui": {
    "page": "options/options.html",
    "open_in_tab": true
  },
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "addons@cheapermail.com",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  }
}