Examine source code of Gmail Thread Extractor

{
  "manifest_version": 3,
  "name": "Gmail Thread Extractor",
  "description": "Extract a Gmail conversation as clean Markdown",
  "version": "0.2.4",
  "icons": {
    "16": "icon/16.png",
    "48": "icon/48.png",
    "128": "icon/128.png"
  },
  "permissions": [
    "storage",
    "activeTab",
    "clipboardWrite"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{bfe19365-e157-4f6b-a998-b62419000a5a}",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "action": {
    "default_title": "Gmail Thread Extractor",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://mail.google.com/*"
      ],
      "js": [
        "content-scripts/gmail.js"
      ]
    }
  ]
}