Examine source code of Em Dash Block

{
  "manifest_version": 3,
  "name": "Em Dash Block",
  "version": "1.0",
  "description": "Highlights paragraphs containing em dashes. Of course, em dashes alone are not a definitive indicator of AI use so please be responsible, but this extension should make it clear when someone is 'overusing' this character.",
  "permissions": [],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "emdashblock@petertanner.dev"
    }
  }
}