Examine source code of Markdown Previewer

{
  "manifest_version": 2,
  "name": "Markdown Previewer",
  "version": "1.0",
  "description": "Write Markdown and preview HTML in real-time, with copy and history features",
  "permissions": [
    "clipboardWrite"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Markdown Previewer"
  },
  "icons": {
    "48": "icon.png"
  },
  "content_security_policy": "script-src 'self' https://cdn.jsdelivr.net; object-src 'self'",
  "browser_specific_settings": {
    "gecko": {
      "id": "{bef699cb-398c-4bcb-af5c-1e96966435c0}"
    }
  }
}