Examine source code of ChatGPT Cleanup

{
  "manifest_version": 2,
  "name": "ChatGPT Cleanup",
  "version": "1.0",
  "description": "Clean up ChatGPT messages, leaving only the last 20.",
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "chatgpt-cleanup@chatgpt-cleanup",
      "strict_min_version": "60.0"
    }
  }
}