Examine source code of YouTube Thumbnail Blocker

{
  "manifest_version": 3,
  "version": "2.5.4",
  "name": "__MSG_extName__",
  "description": "__MSG_extDescription__",
  "browser_specific_settings": {
    "gecko": {
      "id": "{12c9830d-30fa-1733-1c03-9fe0b354c325}"
    },
    "gecko_android": {}
  },
  "icons": {
    "48": "img/icon48.png",
    "128": "img/icon128.png",
    "512": "img/icon512.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "common.js",
        "inject.js"
      ],
      "run_at": "document_start"
    }
  ],
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  },
  "permissions": [
    "storage"
  ]
}