Examine source code of Gmail to Markdown

{
  "manifest_version": 2,
  "name": "Gmail to Markdown",
  "description": "Copies Gmail email as formatted markdown",
  "Author": "Yoav TC",
  "icons": {
    "48": "icons/icon48.png"
  },
  "version": "1.1",
  "permissions": [
    "menus",
    "clipboardWrite",
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "gmail-to-markdown@yourdomain.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://mail.google.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}