Examine source code of Playback Speed Controller

{
  "manifest_version": 3,
  "name": "Playback Speed Controller",
  "version": "1.1.5",
  "description": "Control video and audio playback speed with keyboard shortcuts",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "all_frames": true,
      "js": [
        "storage.js",
        "overlay.js",
        "content.js"
      ],
      "css": [
        "content.css"
      ],
      "run_at": "document_start"
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_page": "options.html",
  "action": {
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png"
    },
    "default_title": "Playback Speed Controller"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "playback-speed-controller@saffet.dev",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}