Examine source code of YouTube Timestamp

{
  "manifest_version": 2,
  "name": "YouTube Timestamp",
  "version": "1.7.2",
  "description": "YouTube動画のタイムスタンプを作成・管理する拡張機能",
  "permissions": [
    "activeTab",
    "storage",
    "clipboardWrite",
    "https://www.youtube.com/*",
    "https://youtube.com/*"
  ],
  "background": {
    "scripts": [
      "assets/js/background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.youtube.com/*",
        "https://youtube.com/*"
      ],
      "exclude_matches": [
        "https://www.youtube.com/embed/*",
        "https://youtube.com/embed/*"
      ],
      "js": [
        "assets/js/content.js"
      ],
      "css": [
        "src/features/recorder/styles/floating-panel.css",
        "src/features/recorder/styles/timestamp-list.css",
        "src/features/recorder/styles/content.css"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_action": {
    "default_popup": "src/app/popup/popup.html",
    "default_title": "YouTube Timestamp",
    "default_icon": {
      "16": "assets/icons/icon-16.png",
      "32": "assets/icons/icon-32.png",
      "48": "assets/icons/icon-48.png",
      "128": "assets/icons/icon-128.png"
    }
  },
  "options_ui": {
    "page": "src/features/manager/index.html",
    "open_in_tab": true
  },
  "icons": {
    "16": "assets/icons/icon-16.png",
    "32": "assets/icons/icon-32.png",
    "48": "assets/icons/icon-48.png",
    "128": "assets/icons/icon-128.png"
  },
  "web_accessible_resources": [
    "src/features/recorder/styles/*.css",
    "assets/icons/*.png"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "bca28d25-dfa5-f8e1-f8ca-3fbece7c5d19@nasyue.github.io",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}