Examine source code of YouTube Party Lights

{
  "manifest_version": 3,
  "name": "YouTube Party Lights",
  "version": "2.1",
  "description": "Music-reactive party light effects for YouTube and YouTube Music. Firefox only.",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon16.png",
      "48": "icon48.png",
      "128": "icon128.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.youtube.com/*",
        "https://music.youtube.com/*",
        "https://youtu.be/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "host_permissions": [
    "https://www.youtube.com/*",
    "https://music.youtube.com/*",
    "https://youtu.be/*"
  ],
  "commands": {
    "_execute_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+L"
      },
      "description": "Toggle Party Lights"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "youtubepartylights@thugon.com",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}