Examine source code of YouTube Speed Controller

{
  "manifest_version": 3,
  "name": "YouTube Speed Controller",
  "version": "1.4.9",
  "description": "Control YouTube video playback speed with ,, ., and / keys, with optional display.",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "action": {
    "default_icon": {
      "16": "icon16.png",
      "48": "icon48.png",
      "128": "icon128.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ]
    }
  ],
  "commands": {
    "toggle-display": {
      "suggested_key": {
        "default": "Ctrl+Shift+S"
      },
      "description": "Toggle speed display"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "yt-speed-controller-unique-id-2026@soohoon.lee",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}