Examine source code of YT Speed Quick Access

{
  "manifest_version": 2,
  "name": "YT Speed Quick Access",
  "version": "1.0",
  "description": "Adds customizable preset buttons to control Youtube video playback speed",
  "permissions": [
    "storage",
    "activeTab",
    "*://*.youtube.com/*"
  ],
  "browser_action": {
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "images/icon-16.png",
      "32": "images/icon-32.png",
      "48": "images/icon-48.png",
      "128": "images/icon-128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "content/content.js"
      ],
      "css": [
        "content/content.css"
      ]
    }
  ],
  "icons": {
    "16": "images/icon-16.png",
    "32": "images/icon-32.png",
    "48": "images/icon-48.png",
    "128": "images/icon-128.png"
  },
  "web_accessible_resources": [
    "icons/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "ytspeedquickaccess@firefox-addon",
      "strict_min_version": "79.0"
    }
  }
}