Examine source code of Yahoo Pick Pool Tool

{
  "manifest_version": 3,
  "name": "Yahoo Pick Pool Tool",
  "version": "1.3",
  "browser_specific_settings": {
    "gecko": {
      "id": "footballodds@jasondekarske.com",
      "strict_min_version": "109.0"
    }
  },
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://football.fantasysports.yahoo.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "action": {
    "default_icon": {
      "48": "arodface-48.png"
    }
  }
}