Examine source code of DeadP47 replacer

{
  "manifest_version": 3,
  "name": "DeadP47 replacer",
  "version": "1.0",
  "description": "Заменяет выбранные слова на YouTube",
  "browser_specific_settings": {
    "gecko": {
      "id": "deadp47-replacer@tvoedomen.ru",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "16": "111.jpg",
    "48": "111.jpg",
    "128": "111.jpg"
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/*",
        "*://youtu.be/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ]
}