Examine source code of Codefroces

{
  "manifest_version": 3,
  "name": "Codefroces",
  "version": "1.67",
  "description": "Changes the Codeforces logo to CODEFROCES",
  "browser_specific_settings": {
    "gecko": {
      "id": "codefroces-replacer@yourname.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "activeTab"
  ],
  "icons": {
    "48": "icon.png"
  },
  "action": {
    "default_icon": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.codeforces.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_end"
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "codefroces.png"
      ],
      "matches": [
        "*://*.codeforces.com/*"
      ]
    }
  ]
}